Will Windows 7 cure update problems?

I have a Dell XPS M1330 running Vista, which I recently had to reinstall due to malware that had rendered the computer inoperable.  After reinstalling, many of the Vista updates, including SP1, have failed to take.  I've tried disabling the UAC, but the updates still fail.  I'm wondering if the simplest fix at this point is to simply do a clean install of Windows 7.  Any thoughts on whether that is likely to work, or am I throwing in the towel too soon?

Thanks.