Well, if you wanna have clean system, you have to be aware that all those different antivirus leftovers will just give you even more troubles... you mentioned Norton (antivirus I believe)... that guy is killing with avast!. Also, you mentioned ZA. I guess you meant on Zone Alarm antivirus, and not on ZA firewall, since firewalls in general won't be on your way... Of course, you may experience additional problems if you wanna run Norton firewall and ZA firewall in the same time. If you meant on Norton antivirus, then Norton is third antivirus you mentioned. I'm not sure 'cause I can't check your system from here, but I believe that everything in messed up over there... especially when you say that you are experiencing so many different problems... you have to decide which one of those programs do you want to use... either avast!, or Norton antivirus or some third product... can't use them all in the same time on the same machine without causing those troubles.
My advice is... clean your system completely (even if that requires complete format and re-installation of your OS)... sometimes there is no other solution, but that doesn't mean you will lose your personal documents and stuff. If you search these threads a little, I'm sure you'll get tons of posts (I posted in many of them) explaining how important is to perform back ups of your system on regular basis. If you did that, you wouldn't have these problems now. I'm not talking about System restore... that's a child's play comparing to real backup tools. You need something like Ghost or some other back-up utility. You can back up just one partition to image file or if you like, you can backup whole system in just about 10 minutes... when some problems like this occurs with your system, you can just take one of those backup image files, and restore your system to any of those previous safe points in about 5 minutes. No hassle, nothing... but to be able to do that, you should have been made that backup while your system was still in good condition... I am afraid, if you want to have clean system as you had before these problems started to appear, there is nothing else than just reformat everything and start all over again. There is just too many problems on your system, and I'm sure it would be very very hard to locate all of them, even if I am close to your system right now... sometimes there is nothing else to do, than to clean it from the scratch. No one will do that for you, and your system won't heal all of a sudden... you'll just go into problems deeper and deeper, because one will invoke another one and so on, and so on... sometimes, systems become so "dirty" that there is no utility in the world that can clean them up.
Btw, by "repair work" I meant on Windows XP reapir function. Sometimes, you don't have to reinstall everything from the scratch (some minor problems and situations), it's enough to proceed with Windows XP reapir. You will have to use your original Windows XP cd. Google little bit and you'll find thousands of pages explaining how to perform repair of your OS. One of them is this one:
http://www.michaelstevenstech.com/XPrepairinstall.htmNote: Read carefully every single word that guy wrote over there, and don't just press OK and/or CANCEL... it's very important to follow every single step he explained on that page...But, still... I am sure in your case, best possible thing would be to format your HD and start all over again... Of course it's up to you... but you'll just have more and more problems.
Cheers !