I'm trying to have perfmon counters to work both in 32bit and 64bit modes of the perfmon. I have two builds of my coutners dll, one in c:\windows\system32, the other in c:\windows\syswow64 folder. I can't get both of them to work at the same time though, only one at a time. As a matter of fact I can't even figure out what determines which one of them works, but it seems that I have to run lodctr to switch between them.