Squeegee

Needs at least 2GHz to run at a playable speed. As soon as you run the program, go to Task Manager -> Processes, right click mainsys.exe and set the priority to high. If the sound stutters, close the game and repeat (Task Manager will be in memory and should load instantly). Once done, put a few coins in or trigger the alarm to see if the sound's OK. If so, try to get something remotely decent on these nasty games!

Setting the priority to high gives the game full speed and also lets you use the computer for minor things without the sound going out of sync.

Runs fine on 2.8GHz Celeron, runs terrible on a 1.2GHz machine. They weren't coded to be 'friendly', and I'm not even sure if they are actually emulators at all (only the actual game code from the ROM is in the EXE file, but it is patched to access memory in the Win32 400000 range). Can't see any SH-4 emulator code in there either.

Are we talking about the same 4 games here?
As i can play these games fine with no slowdown or sound problems on a P3 800Mhz -384mb ram-and a old Pci 64meg graphics card
I have tried using them on xp and they dont run at all but under windows 98/Me runs fine