I had been noticing tht my comp was getting slower and slower over that last 15-20 days. On starting the comp, it took a long time for windows to start and there used to be a lengthy period when the screen went blank and the cursor changed to waiting (just before logon screen appeared i.e.). Also, browsers seemed to hang for a min. occasionally before they came back to life when browsing on random web sites.

Now wat has happened is that the process winlogon.exe is taking up almost 100% CPU usage after booting windows. It takes an eternity for login to actually happen and another eternity for the desktop icons, taskbar, etc to appear. Even the taskmanager took a long time to come up then I could see that winlogon.exe was hogging all the CPU usage.

Somebody help me plz...this is pretty urgent

Were you on a network and had some network drives mapped? Also, were you possibly connected to a domain?

I was connected to the institute LAN via the ethernet card, which in turn was connected to the net thru a proxy server.

Unmap any network drives and ensure you're no longer on the domain. Also, removed the proxy settings... they'll likely do you no good unless you're connected to the institute's network.

Oh I got rid of the problem for now ...actually I searched for winlogon in my drive and found a pre-fetch file winlogon.exe-******.pf (some numbers and alphabet) which had the modification date and appx. time since when this had started happening. I used Cleanup to delete all pre-fetch files and since then the comp's been working fine.
Thanks for replying though...