Follow the steps in this post to verify your system is clean. - How do I get rid of malicious spyware, malware, viruses or rootkits from my PC?How do I get rid of malicious spyware, malware, viruses or rootkits from my PC?
It may be a good idea to run SFC (system file checker) to verify the integrity of Windows files.
After all that, try installing the drivers by launching them from the context menu (right click) with Run as Administrator.
