systems failure - psapi.dll

Hi All

I have ballsed up pretty badly.

Had psap.dll error message on startup which having consulted various threads saw on microsoft forums that this could be resolved by searching for the latest psapi.dll & changing its name to whatever, as it was the latest app install which created the issue by installing an older version of this file.

I searched directories & system folders & found many such files, 4 had the same latest date of which 2 of these were in system32 directories & the other 2 were in another sys folder i cannot remember which though.
Some of the MS forum posts had changed all of these .dll names & said they had no problems, so i was confident if i only changed the latest versions i should be ok.
I changed the filename & a op system warning came up about changing these file names...saying reinstall the WinXP op system cd.

Obviously i had done something very wrong.

I tried to register another psapi.dll in cmd prompt through regsr32 & pathname & then rebooted.

On reboot i now have blue screen - systems failure & obviously the reboot stops here.

Can i open in safe mode etc & revert my changes?
Your help is much appreciated.
Thanks,
R

 

i would really appreciate a response - i cannot open win xp in safe mode.....the blue screen with fata system error still coming up.

need to know if theres any hope of recovery?