I would like to make an official statement here.
Official Statement from Association of the Protection of Cue's Sanity
Windows 7 has no known issues with SRB2 directly, neither 32-bit or 64-bit has any problems, many of the developers run SRB2 on Windows 7 and I personally use 64-bit Windows 7 Ultimate in a domain environment (think corporate) which is about as problematic as it gets with games and programs, and experience no issues with SRB2.
Any issues you have with SRB2 are due to drivers and such, if your computer is quite old, chances are your drivers aren't even Win7 compatible. Also, it may be that your PC is just sucky. And please check your network device drivers mostly, but also all your other drivers. To reiterate, Windows 7 does not have any issues with running on any version of Windows except for those issues which span all versions, it is an isolated problem down to your hardware/configuration, most likely a configuration error.
/end statement.