After doing a McAfee Virus Scan, it picked up a file it said was unnecessary. Couldn't check it at the time so went to delete another file but erased this one instead. Now computer keeps asking for: RUN DLL Cannot find file: C:\WINDOWS\SYSTEM\MSA64CHK.DLL. Second hand computer, don't know a lot about it and I'm just learning how to use one. Please can you help me? Many thanks

You can download it here and follow the instructions. http://www.dll-files.com/dllindex/dl...shtml?msa64chk