The patch MS06-015 which validates shell extensions has caused quite a number of problems with HP, and NVidia software. A number of my friends that do IT support have told me about the large number of computers they have seen affected by this problem.
Microsoft has indicates that they will be releasing an update to this patch soon. But if you have had problems right clicking on the desktop (Windows freezes up). You may want to consider using this temp fix from MS:
(Please backup your registry and system before making any registry changes!! – Make a mistake and your machine wont boot again)
1. Log on to the computer by using an account that has administrative credentials.
2. Click Start, click Run, type regedit, and then click OK.
3. Locate and then right-click the following registry subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Shell Extensions\Cached
4. Point to New, and then click DWORD Value.
5. For Microsoft Windows 2000-based computers, type the following:
{A4DF5659-0801-4A60-9607-1C48695EFDA9} {000214E6-0000-0000-C000-000000000046}
For Microsoft Windows XP-based or Microsoft Windows Server 2003-based computers, type the following:
{A4DF5659-0801-4A60-9607-1C48695EFDA9} {000214E6-0000-0000-C000-000000000046} 0×401
6. Right-click the value that you just created, and then set the Value data to 1
7. Exit Registry Editor.
8. Use Task Manager to close the Verclsid.exe program or to restart the computer.