Thanks Boggin but I will wait to hear from Shane in case he may have another lead to what is going on but I will keep your advice in mind. 
I don't know if the following is any help in resolving the problem:
I soft shutdown the computer at approx. 8.56pm tonight which took 2m.20s. I started it up again at approx. 9.03pm which took 6 min.
It booted up without any problems. I don't know if the Performance Event logs will be of any help but here they are after the shutdown and starting up at 8.56pm and 9.03pm respectively.  
Log Name:      Microsoft-Windows-Diagnostics-Performance/Operational
Source:        Microsoft-Windows-Diagnostics-Performance
Date:          31/01/2015 09:05:52 PM
Event ID:      101
Task Category: Boot Performance Monitoring
Level:         Warning
Keywords:      Event Log
User:          LOCAL SERVICE
Computer:      home-PC
Description:
This application took longer than usual to start up, resulting in a performance degradation in the system startup process: 
     File Name      :   explorer.exe
     Friendly Name      :   Windows Explorer
     Version      :   6.0.6000.16386 (vista_rtm.061101-2205)
     Total Time      :   9231ms
     Degradation Time   :   6212ms
     Incident Time (UTC)   :   31/01/2015 09:01:02 PM
Event Xml:
<Event xmlns="
http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Diagnostics-Performance" Guid="{cfc18ec0-96b1-4eba-961b-622caee05b0a}" />
    <EventID>101</EventID>
    <Version>1</Version>
    <Level>3</Level>
    <Task>4002</Task>
    <Opcode>33</Opcode>
    <Keywords>0x8000000000010000</Keywords>
    <TimeCreated SystemTime="2015-01-31T21:05:52.889Z" />
    <EventRecordID>18</EventRecordID>
    <Correlation ActivityID="{00000000-86C8-0000-B3BD-A305993DD001}" />
    <Execution ProcessID="2728" ThreadID="3932" />
    <Channel>Microsoft-Windows-Diagnostics-Performance/Operational</Channel>
    <Computer>home-PC</Computer>
    <Security UserID="S-1-5-19" />
  </System>
  <EventData>
    <Data Name="StartTime">2015-01-31T21:01:02.765Z</Data>
    <Data Name="NameLength">13</Data>
    <Data Name="Name">explorer.exe</Data>
    <Data Name="FriendlyNameLength">17</Data>
    <Data Name="FriendlyName">Windows Explorer</Data>
    <Data Name="VersionLength">39</Data>
    <Data Name="Version">6.0.6000.16386 (vista_rtm.061101-2205)</Data>
    <Data Name="TotalTime">9231</Data>
    <Data Name="DegradationTime">6212</Data>
    <Data Name="PathLength">24</Data>
    <Data Name="Path">C:\Windows\explorer.exe</Data>
    <Data Name="ProductNameLength">37</Data>
    <Data Name="ProductName">Microsoft® Windows® Operating System</Data>
    <Data Name="CompanyNameLength">22</Data>
    <Data Name="CompanyName">Microsoft Corporation</Data>
  </EventData>
</Event>
Log Name:      Microsoft-Windows-Diagnostics-Performance/Operational
Source:        Microsoft-Windows-Diagnostics-Performance
Date:          31/01/2015 09:05:52 PM
Event ID:      100
Task Category: Boot Performance Monitoring
Level:         Error
Keywords:      Event Log
User:          LOCAL SERVICE
Computer:      home-PC
Description:
Windows has started up: 
     Boot Duration      :   90866ms
     IsDegradation      :   false
     Incident Time (UTC)   :   31/01/2015 09:01:02 PM
Event Xml:
<Event xmlns="
http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Diagnostics-Performance" Guid="{cfc18ec0-96b1-4eba-961b-622caee05b0a}" />
    <EventID>100</EventID>
    <Version>1</Version>
    <Level>2</Level>
    <Task>4002</Task>
    <Opcode>34</Opcode>
    <Keywords>0x8000000000010000</Keywords>
    <TimeCreated SystemTime="2015-01-31T21:05:52.889Z" />
    <EventRecordID>17</EventRecordID>
    <Correlation ActivityID="{00000000-86C8-0000-B3BD-A305993DD001}" />
    <Execution ProcessID="2728" ThreadID="3932" />
    <Channel>Microsoft-Windows-Diagnostics-Performance/Operational</Channel>
    <Computer>home-PC</Computer>
    <Security UserID="S-1-5-19" />
  </System>
  <EventData>
    <Data Name="BootTsVersion">2</Data>
    <Data Name="BootStartTime">2015-01-31T21:01:02.765Z</Data>
    <Data Name="BootEndTime">2015-01-31T21:05:35.215Z</Data>
    <Data Name="SystemBootInstance">2431</Data>
    <Data Name="UserBootInstance">2405</Data>
    <Data Name="BootTime">90866</Data>
    <Data Name="MainPathBootTime">72366</Data>
    <Data Name="BootKernelInitTime">24</Data>
    <Data Name="BootDriverInitTime">5160</Data>
    <Data Name="BootDevicesInitTime">9525</Data>
    <Data Name="BootPrefetchInitTime">33081</Data>
    <Data Name="BootPrefetchBytes">502403072</Data>
    <Data Name="BootAutoChkTime">0</Data>
    <Data Name="BootSmssInitTime">20596</Data>
    <Data Name="BootCriticalServicesInitTime">3120</Data>
    <Data Name="BootUserProfileProcessingTime">1203</Data>
    <Data Name="BootMachineProfileProcessingTime">178</Data>
    <Data Name="BootExplorerInitTime">27698</Data>
    <Data Name="BootNumStartupApps">18</Data>
    <Data Name="BootPostBootTime">18500</Data>
    <Data Name="BootIsRebootAfterInstall">false</Data>
    <Data Name="BootRootCauseStepImprovementBits">129</Data>
    <Data Name="BootRootCauseGradualImprovementBits">0</Data>
    <Data Name="BootRootCauseStepDegradationBits">8388608</Data>
    <Data Name="BootRootCauseGradualDegradationBits">0</Data>
    <Data Name="BootIsDegradation">false</Data>
    <Data Name="BootIsStepDegradation">false</Data>
    <Data Name="BootIsGradualDegradation">false</Data>
    <Data Name="BootImprovementDelta">133923</Data>
    <Data Name="BootDegradationDelta">0</Data>
    <Data Name="BootIsRootCauseIdentified">true</Data>
  </EventData>
</Event>
Log Name:      Microsoft-Windows-Diagnostics-Performance/Operational
Source:        Microsoft-Windows-Diagnostics-Performance
Date:          31/01/2015 09:05:38 PM
Event ID:      203
Task Category: Shutdown Performance Monitoring
Level:         Warning
Keywords:      Event Log
User:          LOCAL SERVICE
Computer:      home-PC
Description:
This service caused a delay in the system shutdown process: 
     File Name      :   DPS
     Friendly Name      :   WDI Diagnostic Policy Service
     Version      :   6.0.6001.18000 (longhorn_rtm.080118-1840)
     Total Time      :   6984ms
     Degradation Time   :   3754ms
     Incident Time (UTC)   :   30/01/2015 11:34:59 PM
Event Xml:
<Event xmlns="
http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Diagnostics-Performance" Guid="{cfc18ec0-96b1-4eba-961b-622caee05b0a}" />
    <EventID>203</EventID>
    <Version>1</Version>
    <Level>3</Level>
    <Task>4007</Task>
    <Opcode>41</Opcode>
    <Keywords>0x8000000000010000</Keywords>
    <TimeCreated SystemTime="2015-01-31T21:05:38.975Z" />
    <EventRecordID>16</EventRecordID>
    <Correlation ActivityID="{00000000-86C8-0000-B2BD-A305993DD001}" />
    <Execution ProcessID="2728" ThreadID="3880" />
    <Channel>Microsoft-Windows-Diagnostics-Performance/Operational</Channel>
    <Computer>home-PC</Computer>
    <Security UserID="S-1-5-19" />
  </System>
  <EventData>
    <Data Name="StartTime">2015-01-30T23:34:59.135Z</Data>
    <Data Name="NameLength">4</Data>
    <Data Name="Name">DPS</Data>
    <Data Name="FriendlyNameLength">30</Data>
    <Data Name="FriendlyName">WDI Diagnostic Policy Service</Data>
    <Data Name="VersionLength">42</Data>
    <Data Name="Version">6.0.6001.18000 (longhorn_rtm.080118-1840)</Data>
    <Data Name="TotalTime">6984</Data>
    <Data Name="DegradationTime">3754</Data>
    <Data Name="PathLength">28</Data>
    <Data Name="Path">C:\Windows\system32\dps.dll</Data>
    <Data Name="ProductNameLength">37</Data>
    <Data Name="ProductName">Microsoft® Windows® Operating System</Data>
    <Data Name="CompanyNameLength">22</Data>
    <Data Name="CompanyName">Microsoft Corporation</Data>
  </EventData>
</Event>
Log Name:      Microsoft-Windows-Diagnostics-Performance/Operational
Source:        Microsoft-Windows-Diagnostics-Performance
Date:          31/01/2015 09:05:38 PM
Event ID:      201
Task Category: Shutdown Performance Monitoring
Level:         Warning
Keywords:      Event Log
User:          LOCAL SERVICE
Computer:      home-PC
Description:
This application caused a delay in the system shutdown process: 
     File Name      :   spoolsv.exe
     Friendly Name      :   Spooler SubSystem App
     Version      :   6.0.6000.16386 (vista_rtm.061101-2205)
     Total Time      :   232ms
     Degradation Time   :   120ms
     Incident Time (UTC)   :   30/01/2015 11:34:59 PM
Event Xml:
<Event xmlns="
http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Diagnostics-Performance" Guid="{cfc18ec0-96b1-4eba-961b-622caee05b0a}" />
    <EventID>201</EventID>
    <Version>1</Version>
    <Level>3</Level>
    <Task>4007</Task>
    <Opcode>41</Opcode>
    <Keywords>0x8000000000010000</Keywords>
    <TimeCreated SystemTime="2015-01-31T21:05:38.975Z" />
    <EventRecordID>15</EventRecordID>
    <Correlation ActivityID="{00000000-86C8-0000-B2BD-A305993DD001}" />
    <Execution ProcessID="2728" ThreadID="3880" />
    <Channel>Microsoft-Windows-Diagnostics-Performance/Operational</Channel>
    <Computer>home-PC</Computer>
    <Security UserID="S-1-5-19" />
  </System>
  <EventData>
    <Data Name="StartTime">2015-01-30T23:34:59.135Z</Data>
    <Data Name="NameLength">12</Data>
    <Data Name="Name">spoolsv.exe</Data>
    <Data Name="FriendlyNameLength">22</Data>
    <Data Name="FriendlyName">Spooler SubSystem App</Data>
    <Data Name="VersionLength">39</Data>
    <Data Name="Version">6.0.6000.16386 (vista_rtm.061101-2205)</Data>
    <Data Name="TotalTime">232</Data>
    <Data Name="DegradationTime">120</Data>
    <Data Name="PathLength">32</Data>
    <Data Name="Path">C:\Windows\System32\spoolsv.exe</Data>
    <Data Name="ProductNameLength">37</Data>
    <Data Name="ProductName">Microsoft® Windows® Operating System</Data>
    <Data Name="CompanyNameLength">22</Data>
    <Data Name="CompanyName">Microsoft Corporation</Data>
  </EventData>
</Event>
Log Name:      Microsoft-Windows-Diagnostics-Performance/Operational
Source:        Microsoft-Windows-Diagnostics-Performance
Date:          31/01/2015 09:05:38 PM
Event ID:      201
Task Category: Shutdown Performance Monitoring
Level:         Warning
Keywords:      Event Log
User:          LOCAL SERVICE
Computer:      home-PC
Description:
This application caused a delay in the system shutdown process: 
     File Name      :   Mini_Monitor.exe
     Friendly Name      :   CleanMem Mini Monitor
     Version      :   2.5.0.0
     Total Time      :   2654ms
     Degradation Time   :   2207ms
     Incident Time (UTC)   :   30/01/2015 11:34:59 PM
Event Xml:
<Event xmlns="
http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Diagnostics-Performance" Guid="{cfc18ec0-96b1-4eba-961b-622caee05b0a}" />
    <EventID>201</EventID>
    <Version>1</Version>
    <Level>3</Level>
    <Task>4007</Task>
    <Opcode>41</Opcode>
    <Keywords>0x8000000000010000</Keywords>
    <TimeCreated SystemTime="2015-01-31T21:05:38.975Z" />
    <EventRecordID>14</EventRecordID>
    <Correlation ActivityID="{00000000-86C8-0000-B2BD-A305993DD001}" />
    <Execution ProcessID="2728" ThreadID="3880" />
    <Channel>Microsoft-Windows-Diagnostics-Performance/Operational</Channel>
    <Computer>home-PC</Computer>
    <Security UserID="S-1-5-19" />
  </System>
  <EventData>
    <Data Name="StartTime">2015-01-30T23:34:59.135Z</Data>
    <Data Name="NameLength">17</Data>
    <Data Name="Name">Mini_Monitor.exe</Data>
    <Data Name="FriendlyNameLength">22</Data>
    <Data Name="FriendlyName">CleanMem Mini Monitor</Data>
    <Data Name="VersionLength">8</Data>
    <Data Name="Version">2.5.0.0</Data>
    <Data Name="TotalTime">2654</Data>
    <Data Name="DegradationTime">2207</Data>
    <Data Name="PathLength">43</Data>
    <Data Name="Path">C:\Program Files\CleanMem\Mini_Monitor.exe</Data>
    <Data Name="ProductNameLength">22</Data>
    <Data Name="ProductName">CleanMem Mini Monitor</Data>
    <Data Name="CompanyNameLength">14</Data>
    <Data Name="CompanyName">PcWinTech.com</Data>
  </EventData>
</Event>
Log Name:      Microsoft-Windows-Diagnostics-Performance/Operational
Source:        Microsoft-Windows-Diagnostics-Performance
Date:          31/01/2015 09:05:38 PM
Event ID:      200
Task Category: Shutdown Performance Monitoring
Level:         Critical
Keywords:      Event Log
User:          LOCAL SERVICE
Computer:      home-PC
Description:
Windows has shutdown: 
     Shutdown Duration   :   76957666ms
     IsDegradation      :   false
     Incident Time (UTC)   :   30/01/2015 11:34:59 PM
Event Xml:
<Event xmlns="
http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Diagnostics-Performance" Guid="{cfc18ec0-96b1-4eba-961b-622caee05b0a}" />
    <EventID>200</EventID>
    <Version>1</Version>
    <Level>1</Level>
    <Task>4007</Task>
    <Opcode>40</Opcode>
    <Keywords>0x8000000000010000</Keywords>
    <TimeCreated SystemTime="2015-01-31T21:05:38.975Z" />
    <EventRecordID>13</EventRecordID>
    <Correlation ActivityID="{00000000-86C8-0000-B2BD-A305993DD001}" />
    <Execution ProcessID="2728" ThreadID="3880" />
    <Channel>Microsoft-Windows-Diagnostics-Performance/Operational</Channel>
    <Computer>home-PC</Computer>
    <Security UserID="S-1-5-19" />
  </System>
  <EventData>
    <Data Name="ShutdownTsVersion">1</Data>
    <Data Name="ShutdownStartTime">2015-01-30T23:34:59.135Z</Data>
    <Data Name="ShutdownEndTime">2015-01-31T20:57:36.802Z</Data>
    <Data Name="ShutdownTime">76957666</Data>
    <Data Name="ShutdownUserSessionTime">21292</Data>
    <Data Name="ShutdownUserPolicyTime">339</Data>
    <Data Name="ShutdownUserProfilesTime">151</Data>
    <Data Name="ShutdownSystemSessionsTime">10677</Data>
    <Data Name="ShutdownPreShutdownNotificationsTime">6524</Data>
    <Data Name="ShutdownServicesTime">1997</Data>
    <Data Name="ShutdownKernelTime">76925696</Data>
    <Data Name="ShutdownRootCauseStepImprovementBits">0</Data>
    <Data Name="ShutdownRootCauseGradualImprovementBits">0</Data>
    <Data Name="ShutdownRootCauseStepDegradationBits">0</Data>
    <Data Name="ShutdownRootCauseGradualDegradationBits">0</Data>
    <Data Name="ShutdownIsDegradation">false</Data>
    <Data Name="ShutdownTimeChange">0</Data>
  </EventData>
</Event>