Use more than a local newspaper reference for a file download
Especially for AV, there are TONS upton TONS of reviews for free, great software. Do your research prior to downloading anything.
Definately bogus software then, it probably corrupted some system files if a safemode boot won't fix the issue since safemode only loads the most essential drivers and software.
Luckily for your Vista doesn't offer a repair installation so you are SOL (sarcasm, i really hate that Vista doesn't provide a repair option).