WMI - Failed to connect

WMI (Windows Management instrumentation) service had been an issue recently in most of the installation like SQL Server 2005, SQL BPA etc. There are many solutions provided on the net, having tried almost all, only the following worked at last - Rebuilding WMI

Comprehensive rebuild methodImportant note:
If you've installed a Service Pack, you need to insert your Windows XP CD with Service Pack integration (called as the Slipstreamed Windows XP CD). If you don't have one, you may point to the %Windir%\ServicePackFiles\i386 folder for a recent version of the system files required during WMI repair. Or you may create a slipstreamed Windows XP CD and insert it when prompted.
Click Start, Run and type the following command, and press ENTER:

rundll32.exe setupapi,InstallHinfSection WBEM 132
%windir%\inf\wbemoc.inf

Insert your Windows XP CD into the drive when prompted. Repair process should take few minutes to complete. Then restart Windows for the changes to take effect.

Note: Do not copy wmiprvse.exe while rebuilding. Remove this file from the %Windir%\ServicePackFiles\i386 folder, if exists, then start rebuilding. This file will cause CPU spike.

Reference: http://windowsxp.mvps.org/repairwmi.htm