Computer will not restart

The computer will not power-off. It gets to the blue screen, with the Windows XP logo, and says: "Logging off..." then "Saving Settings...", then hangs on: "Windows is shutting down..."

Any suggestions?

 

It was left for 20mins once. XP Pro with SP3

 

It happened after installing Windows updates. Computer reboots normally after forced shutdown.

 

I don't like to use the word "never" but a 20 min hang would make it a reasonable assumption.

Microsoft .NET Framework 2.0 Service Pack 1 (KB110806) (x86) Friday, October 24, 2008 Microsoft Update
Windows XP Windows Internet Explorer 7 for Windows XP Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB958644) Friday, October 24, 2008 Microsoft Update
Silverlight Microsoft Silverlight (KB957938) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB957095) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB956841) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB956803) Friday, October 24, 2008 Microsoft Update
Windows XP Cumulative Security Update for ActiveX Killbits for Windows XP (KB956391) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB954211) Friday, October 24, 2008 Microsoft Update
Windows XP Windows Malicious Software Removal Tool - October 2008 (KB890830) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB938464) Friday, October 24, 2008 Microsoft Update
Windows XP Update for Windows XP (KB952287) Friday, October 24, 2008 Microsoft Update
Windows XP Update for Windows XP (KB951072) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB950974) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB952954) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB946648) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB951748) Friday, October 24, 2008 Microsoft Update
Windows XP Windows Search 4.0 for Windows XP (KB940157) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB951698) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB951376) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP with Windows Media Format Runtime 9.5 (KB923689) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP (KB950762) Friday, October 24, 2008 Microsoft Update
Windows XP Security Update for Windows XP with Windows Media Format Runtime 9.5 and 11 (KB941569) Friday, October 24, 2008 Microsoft Update
CAPICOM Security Update for CAPICOM (KB931906) Friday, October 24, 2008 Microsoft Update
Windows XP Microsoft .NET Framework 2.0: x86 (KB829019) Friday, October 24, 2008 Microsoft Update
Windows XP Samsung Electronics CO., LTD. - Monitors - Syncmaster 957DF(X)/907DF(X)/900IFT, Syncmaster Magic CD197A(P) Friday, October 24, 2008 Microsoft Update
Windows XP Windows XP Service Pack 3 (KB936929) Friday, October 24, 2008 Microsoft Update
Windows Windows Live Messenger Friday, October 24, 2008 Other Source
Windows XP Update for Windows XP (KB898461) Friday, October 24, 2008 Windows Update
Windows XP Windows Genuine Advantage Validation Tool (KB892130) Friday, October 24, 2008 Windows Update

 

All due respect (I think) but if it was an intermittent problem I would have stated it.
Further, my apologies for the lack of status icons (lost in formatting):they were all green ticks of success

 

Thanks for you help. I hope there's an alternative to formatting.

 

lol. If the quote was discluded I would have sounded rude.