This might be a GQ, but anyways.
I need to slow down my CPU speed fow certain applications I run. Iknow that there are programs that do that, I just don’t know where.
If someone knows I would appreciate also knowing.
i have the same problem, but I have a mac and still haven’t found a program to do it… 
I use one called Moslo for playing early '90s PC games. I don’t know if it’s freeware/shareware or not, so I won’t post any links (besides, I can’t remember where I got it – try trawling abandonware games sites).
Abandonware!
Not linking either, but a few months ago, I found a bonafide copy (well, I GUESS. Could be illegal) of the late 80’s game Stunts. Remember that? You could build your own tracks, with loops and ramps and banked corners and stuff?
FANTASTIC. And still a great game to play, even IF that Countach sounds like a Seiko and looks like a toaster.
As to the OP: not a clue. Sorry.
You can always underclock it. If you have a soft BIOS you can change it during boot up, otherwise you have to switch jumpers, which is much less convienient if you’re switching back and forth very often.