I know this is TOTALLY OFF-TOPIC, but i cant help, and dunno where to go

Anyways, this morning, i reinstalled my windows due to idiotic errors i kept getting, one of them is listed below. And then.. after the reinstallation, i downloaded fresh copies of software installations (here, msn, and norton av2002) and tried to install when i got these errors..
What should be done? (Please dont temme, dump windows for *NIX, I dont like windows myself)
Reinstallation has failed... I formatted C: earlier, but left my D: just like how it is, but i didnt use the installation files from D:.. but i downloaded them from the net, so we dont have any possibilities of a virus.
Error creating process <C:WINDOWSTEMPIXP000.tmpmsiinst.exe /i instmsi.msi REBOOT=REALLYSUPRESS /q>. Reason %1 is not a valid Win32 application.
And then it sez
Cannot find file 'C:WINDOWSSYSTEMmsiexec.exe' (or one of its components). Make sure the path and filename are corrent and that all required libraries are available.
Thanks.
But PLEASE gimme help!!!
