Can this pc be saved?

Brought home a brand new PC from The Wife's office. She had some malaware issue on one of her computers in her workgroup at her office, and I ume something similar found its way inside this new PC which we brought home. I'm not much of a pro so please bare with me, I want to break it down for you so it's clear. She had four or five pc's connected through a switch at her workplace, and her one PC was really acting up - it was the malaware. I came on this Yahoo Answers site, asked about that, and some very knowledgeable helpful people told me to go to malawarebytes.org or something and download free stuff and run some scans and that seemed to have taken care of the problem. Fast fwd a day or three and I take one of her workplace pc's (not the malaware one) home to replace her old home PC. Got it up and running, plugged on the router, cable modem, life is sweet, etc. Then next today, (today) the same problem seems to have popped up. This time it appears to be a different fake-security system trying to p itself off as legit - always the same thing though - "Your computer has a million worms and bugs on it, buy this now and fix it". I tried to navigate to malawarebytes.org with that PC but it always seems to stall - I'm still online but I can't go to that webpage. So I thought I'd restart and I got the blue screen of death instead, telling me in bold white characters to restart in Safe Mode to do something-something, dumping the cache, I forget - something about a cache or whatever, perhaps deleting something, I'm not sure. Prior to restarting I had already gone in Settings, Control Panel, Add/Delete Software and found something that looked like it was the malaware I wanted to get rid of and deleted that, but of course that didn't to do the trick, I was finding leftovers of that fake-antivirus everywhere. Now I have that blue screen still on, I'm in Safe Mode... what do I do? Her PC doesn't currently have an antivirus. She tells me (I just got home) that she managed to buy Norton Anitivirus online but I couldn't find it anywhere. She doesn't know about downloading and installing so I think she never installed it, if she even went so far as to buy it (she printed out the receipt, so....) just maybe downloaded it, but I couldn't find it in Program Files, which I ume is the default storage space for downloaded programs. SO: her pc's in Safe Mode right now, I can't go online with it this way apparently, and I got some serious sh!t happening in that PC. Now what? Thank you SO MUCH guys!!