You might try this (From the MRotate3 help file, ignore the rstimer reference. This procedure is for 64bit XP, not really sure if it's the same for Win7, but it might get you started anyway, I dont have win7 so I cant confirm it.):
You will need to download inpout32 for 64 bit systems. Go to
http://logix4u.net to get this free
download. Place the inpout32 for 64 bit in the C:\Windows\sysWOW64 folder. It's probably best to
also install rstimer.ocx there as well using the install program. The rstimer install program will default to
C:\Windows\System32, at that point, browse to the C:\Windows\sysWOW64 folder and install it there.
Also, do NOT put a copy of inpout32.dll in the same directory as mrotate3.exe. If you do that,
mrotate3.exe will cease to function.
You can also may be able to find info on using it with win 7 on the logix4u website and forum.