Installation fails - Entry point error - SAP GUI 7.20 compilation 3

Hi Experts,

I couldn't install SAP GUI 7.20 compilation 3 in my PC (windows XP 32 Bit SP 3), I used SAP GUI in my PC a year ago but later I formatted my disk. Now when I click on SAPGUISETP it is throwing the following error

*The Procedure entry point ?FeiDbgException@@YAXVCWin32Exception@@@Z could not be located in teh

dynamic link library NwSapFeiLg.dll*

Can anyone please advise?

NB P.s: Initially it mentioned the dll files NWSAPFEIUT.dll & NwSapFeiLg.dll were missing just now I copied them to System & System32 folders. But even though it is showing this entry point error. Also i have done a clean boot and tried installing it but in vain