Problem ! System showing down .. plz help

[gau_pppu]

Computer is slowing down and when I check the task manager it shows 100% CPU usage, there is a file named regsr.exe taking almost 90 to 95% of the CPU.. now if i end that process the CPU usage is coming down to 10 to 20 % ...
but when I turn on my computer next time .. this file coming automatically and CPU usage is showing 100% once again ...

[debsuvra]

Your PC is infected with some type of malware. Scan with a good anti virus software like Kaspersky/NOD32 or Avira Antivir now. Also it is advisable to post HijackThis scan log here.

BTW did you download something like Easy Registry Save/Restore from codeproject.com?