Probably more than you are looking for, but:
Everything You Need To Know To Start Programming 64-Bit Windows Systems
Basically you have two (2) system folders, one for legacy 32bit
dlls/coding [sysWoW64 - "W"indows "o"n "W"indows"64"], the other for
64bit [system32 - old carry-over].
What AV/anti-malware application(s) are you using and what are they
Is the system fully updated?
64bit malware is a bit "newer" and requires a bit more to work
effectively, so most likely you have 32bit malware/crimeware [not that
that makes any difference now]..
So what EXACTLY is it that you have found?
Standard response would be to suggest posting in one of the specialty
Register, and read its posting FAQ *BEFORE* posting.
http://aumha.net/viewtopic.php?t=4075 - Posting FAQ
Windows Info, Diagnostics, Security, Networking
The "real world" of Law, Justice, and Government