i have used 64-bit XP since Beta in 2003 and Vista since Beta in 2006
both work fine, Adobe Photoshop & Premiere supports 64-bit, Paint.NET supports 64-bit, most antivirus supports 64-bit, even my canon printer has 64-bit drivers, for both vista and xp x64, my graphics card, sound card, TV Card i got form ebay, has 64-bit drivers for both xp x64 and vista x64 the only thing i have that dosnt have 64-bit drivers is my phone update software (Sony Ericsson), VirtualDub has 64-bit version, most things has 64-bit version now, so it was a trainwheck in 2004 etc when only 5% of HARDWARE manufactures and software develpers had made 64-bit drivers and software, but NOW its WAY better most software has 64-bit support, and most devinces on motherboards has 64-bit right on the driver cd

and what software does not work?
HIT ME!!! or all spank you