Yet another ? about 2003/2005 LOL

A coworker informed me that I cannot install vb.net 2005 on the same machine as 2003. This has something to do with the 2.0 framework along side of 1.1.

Has anyone had any luck or dismay running these four on the same machine? I wanna start banging on 2005 but can't afford to have problems on my computer right now.