Applications and icons keep closing when selected

help I have problem which started a week ago, I installed quake 4, I also ticked the option for installing direct x 9. (I don't know what version I was running already) since then I have had problems with icons disapearing on my taskbar when right clicking, also pasting text into any program including notebook, IE7 search bar,etc. the programs instantly close down. also if I click on help & support I get a "help and support centre needs to close" message. opening menu bars then picking on an item listed also does the same thing. I have tried to run websetup.exe, with this I get a "setup could bot download file please try again or check connection. I have uninstalled Q4 to no avail I use avg free, & Zonealarm free.

bzr1234,

Good to see you have found this forum, have a browse around as there is lots to read and learn.

I suggest you go to this link and follow exactly what LDTate has suggested.

with kink regards,