.net framework 2.0

i recently installed new video card ati rradeon x850pro 256 mb on my dim 4550. Durind software instal or right at the begining it asked if i have .net framework 2.o. how do i find this info on my computer and if i dont have it do i just download it from microsoft web site. Microsoft .NET Framework Version 2.0 Redistributable Package (x86) and The Microsoft .NET Framework version 2.0 (x64) redistributable package are available and maybe others. Can anyone help? do i need this to get video card full potential?

dim 4550 p4 2.53ghz
1g ddr sdram at 333
win xp sp2
ati radeon x850pro agp 4x