My one and a half cents:

Clothes convertor works OK on my XP machine (P4-2.2 Ghz) with an ATI Radeon 8500 card. It locks up when using certain features, like symmetry mode, so I just avoid those. But I do consider the program "functional", and I have been able to use it to convert V1-Stephanie clothes to V3.

I've also used CC on a Windows 98se, P3-700 machine with an third party ATI 9200se card. It tended to lock up randomly, so I lowered the video hardware acceleration in the Control Panel. It's not an ideal workaround (especially if you're a gamer), but it did stop the random freezes.

Dunno if this will be of any help...