Can't update AV and AS, can't download

My PC is ancient, but it's all I have for now. Lately my Verizon Yahoo Anti-Virus program can't finish it's scans successfully, and the Anti-spy updates won't work either. Also for the past several months, I can't open pdf files, or download the Firefox updates, Adobe updates, etc. I can open jpgs, mpegs, and certain documents.
I've tried turning the firewall off (ZoneLabs free stuff) but to no effect. When I do try to download or open something I get a blank page with "teh object has been blocked" at the top.
Any help will be appreciated.
I use Firefox as my browser, only using the Verizon Yahoo browser very infrequently.
Here is the latest log scan for the AV. Note the incorrect date, although my computer's date is correct.

Started scanning at 1/24/2007 5:19:01 AM. Engine Ver: 30.4.1. Sig Ver:3334. Sig Date: 1/18/2007.
C:\WINDOWS\WIN386.SWP - scan failed.
C:\WINDOWS\Application Data\Mozilla\Firefox\Profiles\jj6en821.Mark\parent.lock - scan failed.
C:\WINDOWS\Internet Logs\fwpktlog.txt - scan failed.
C:\WINDOWS\Internet Logs\fwdbglog.txt - scan failed.
Finished scanning at 1/24/2007 10:15:37 AM.

Thanks.

 

Hi there,

It is really not easy to diagnose what's wrong with a computer, and my suggestion is to start with a scan from 'Kaspersky on line scan':

http://www.kaspersky.com/virusscanner

That will tell you the amount of malware if any on your computer, but it won't clean anything as far as I know (if you do it, you must do it with Internet Explorer, it won't work with Firefox).

Then I would try Ewido free scan: http://www.ewido.net/en/

I think that should clean any spyware it finds.

Another application (if by this stage you can download) that is quite effective is SuperAntiSpyware:

http://www.snapfiles.com/get/SuperAntiSpyware.html

It's free and cleans.

Hopefully some of the real experts might help you.