ok I would suggest using system restore to go back to before everything went bad for you.
If you have not used SR before then please follow these steps.
Go into your control panel and click system and maintainance then go into Backup and Restore and click Use System Restore to fix problems etc. Then click next and choose a time before everything wents bandy. Then follow onscreen instructions.
If you can't find a time then you can try this.
Control Panel/Programs/uninstall programs and select one after another the programs that have been giving you trouble and uninstall them. Only take out those that you can put back if need be. Those you have a copy of on your hard drive etc or the CD . Once everything is as it should be you might want to re install them so don't remove anything you can't put back.
Reset your machine afterwards.
I don't have an extensive arsenal of protection to be online, as most infections are user initiated, going to dodgy sites,clicking unknown links in emails etc etc. All I have is Free AVG(Anti Virus Group) and the regular windows firewall/defender that came with Vista.
Occasionally I use Spybot search and Destroy again free and nothing else really. A site I use a lot for help outside VM is http://www.howtogeek.com/
I hope this helps let us know if it does not.
---------- Post added at 23:21 ---------- Previous post was at 23:14 ----------
It is quite safe to turn all your security off just to see if your system works ok. If it does then its just a process of trial and error to find out which gremlin is screwing things up.
The only security you must keep on is your wireless router apart from that..let it all hang out