I have a 64 bit Windows 7 computer.
I run PBP 2.60 as the compiler.
I use MPASM as the asembler.
I use PICKIT2 as the programmer.
And I use (please don't laugh) CDlite as the editor (I' am an oldfashion guy ).
I do make several different programms a month.
And I dont have any problems at all.

So Windows 7 64bit is a great operating system.