why cann't install any download softwere

anyone knows why i can not install softwere to my pc after i download it? thx

可能是用戶許可權不夠，需要管理員用戶才能有許可權，或者系統中了病毒。

2# 藍藍的天


I'm the administrator of the computer. I think I got virus. Now, I reinstall the system, but I found somone use remote control assistant went through my file after I bought the recovery CD. how can I find out who did that and how to stop that happens. thanks.