Charles,

It is on a local drive or network?

Update:
Can you maybe try compiling it in 8 to see if it's a new 9 problem? I see in the first message you said it happens in 7-9.

In 9 open the Debug Output window before you compile the classlib, is the progress linear or not? What about for the build?

>Nice thought ... I'd forgotten about that ... I unloaded OfficeScan from Trend Micro but to no avail. It still takes over a minute to compile that tiny little class lib.