I've downloaded the newest gpib driver package ni4882_302. It is an executable file, but it is not starting. I've tried to execute it on different Windows machines (Win7 64-Bit and Win-XP 32-Bit). On Win7 I get at least an error message, which says that the Windows version is wrong (but the driver package should work for all these Windows versions including 32- and 64-Bit). On WinXP I get nothing.
The download is in the form of a self-extracting archive. If you cannot even run the exe to extract the installer, it sounds like your download is corrupt. Try downloading the file again. After seeing your post, I downloaded the file from ni.com, and it seems to run just fine.