Strange,
Well I checked what is required to upgrade to Win7 and you look ok -
http://windows.microsoft.com/en-GB/w...m-requirements
I have Win7 64bit and used the jsgme to mod other games with no problems.
Can't understand why fm_interiors. Version 2.1D gives you a CTD when it's enable alone after following the good advice already given.
You could try checking that your zip software is unpacking the file correctly, I have found that some older versions of winzip unpack with file corruption, especially a 7z file.
Then I'd try installing and running fm_interiors. Version 2.1D without other mods and without SH3commander making sure it has done a rollback first. Reason to try this, is that Sh3Commander can change some files before starting SH3.
I looked at fm_interiors and it doesn't alter menu_1024_768.ini which should make things easy. The files most likely to conflict with other mods are Cameras.dat and Commands_en.cfg.
I doubt these suggestions will help your problem, but at least I've bumped your thread. Hope you solve it.