A system restart from a previous installation or update is pending sharepoint 2010

 when running Setup.exe for Microsoft SharePoint Server 2010 you may experience the error:

Setup is unable to proceed due to the following error(s): 
A system restart from a previous installation or update is pending. Restart your computer and run setup to continue. 
For the list of pre-requisites needed to install the product please refer to: 
http://go.microsoft.com/fwlink/?LinkId=106209 
Correct the issue(s) listed above and re-run setup.

Check the value of the following Registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\UpdateExeVolatile - if the value of the UpdateExeVolatileRegistry key is anything other than 0 you will see this message.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\PendingFileRenameOperations - if the PendingFileRenameOperations Registry key has any value you will see this message.

To remove an orphaned UpdateExeVolatile registry key value

1. Open a registry editor, such as Regedit.exe or Regedt32.exe.
2. Navigate to HKLM\SOFTWARE\Microsoft\Updates\
3. In the right navigation pane, double-click the UpdateExeVolatile key.
4. Configure the key with a value of 0
5. Close Registry Editor.

To delete the orphaned PendingFileRenameOperations registry key

1. Open a registry editor, such as Regedit.exe or Regedt32.exe.
2. Navigate to HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\
3. In the right navigation pane, right-click the PendingFileRenameOperations key and select Delete.
4. Close Registry Editor.