Cant install update 2 for WMC 2005

I've had WMC2005 for a week or two and its been working fine with my xbox 360
and i think i removed something today on add or remove programs and my 360
wouldnt connect to my WMC PC. I removed everything off my pc, (i.e. Windows
media center extender, Windows media connect, .NET Framework etc) basically
everything to do with WMC 2005 and when i tried to re install update 2
through www.xbox.com/pcsetup it says 'System Error'. I also tried installing
it through the disc i got with windows media center which is update rollup 2
but on a disc and that doesnt work either. I go through the settings and
click restart and its still version 2002 in my system properties. I need help
please. Thanks