My steam exe wont run?

-Whenever I try to open steam i get this error

"Windows cannot access the specified device path or file. You may not have the appropriate permission to access this item"

I tried starting steam from my desktop and from the Steam directory

The Steam exe also doesn't have its icon,

Iv'e tried to repair it with the Steam installer but I get "Error 1321. Windows installer has insufficient privileges to modify this file C:\Program File\Steam\Steam.exe"

Can some one help me? I'd really appreciate it.