Windows 7 is a valuable upgrade delivering an awesome, new user interface, but don’t expect any major improvements in security.

Anti-virus software vendor Sophos tested Windows 7’s built-in anti-virus capabilities by feeding a clean system 10 pieces of the newest malware. Eight out of the 10 samples ran successfully, claims Sophos.

“Unfortunately, despite Microsoft’s claims, Windows 7 disappointed just like earlier versions of Windows,” says Chester Wisniewski, a senior security advisor at Sophos, in a blog post. “The good news is that, of the freshest 10 samples that arrived, 2 would not operate correctly under Windows 7.”

Sophos’ findings aren’t surprising: Windows 7 promises backward compatibility with most software that works on older operating systems, such as Windows XP. It would be reasonable to infer most malware compatible with Windows XP or Windows Vista is likely going to harm Windows 7.

Also, prior to the release of Windows 7, Microsoft did not promise that the OS would be safer against viruses. Security enhancements that Microsoft highlighted were au