I have a serious Problem with my system ......... my knowledge base is primarily software and internet and I only possess a rudimentary knowledge of OS's and hardware.

I use Windows XP Home and Im pretty sure that my problem is trojan or worm related rather than viral.
I'll try to structure this as well as possible, so not to make it too confusing:

The main problem facing me now (literally) is that I get a persistent box popping up saying: "Internet Explorer has encountered a problem and needs to close. We are sorry for the inconvenience." This happens every few seconds. Its caused by my problem and I have uninstalled IE and denied permissions for it through my firewall (Kerio Personal) in an attempt to contain it - that hasn't worked and I still have the problem.

I don't know if there is a windows background process associated with IE, but when Iv went into my version of WinTasks to check on this, I lose my desktop when I shut down or minimize WinTasks
and then have to reboot again. So I can't really use my WinTasks.

I also get advert windows popping up and arbitrarily resizing my internet windows (I use FireFox), I'v never had pop ups or adverts before and never, ever had my windows buzzing around and resizing themself.
I detected 'Internet Optimizer' on my system, which is either a trojan or spyware (so much of it lately I forget which) that is allegedly very hard to uninstall and causes the activity I just explained. I have uninstalled it in the Control Panel, let Spyware Nuker 2005 auto uninstall it, found it again with the unpaid version of SpyHunter and manually deleted it from the registry and yet I am still seeing the effects.

In doing research into the differant types of executables that are on my system (through Wintasks and my firewall), I will see that some are necessary for the 'stability and security of the system' buy are also associated with certain worms or trojans ex. svchost.exe and others.

On restarts/reboots, when my desktop finally comes up, I see an alert saying that .../system32/kernels32.exe cant be found ........ I have researched this one too, and it says it is also associated with a trojan of some sort, so I am reluctant to try to replace it - though I have no clue why Id get this alert for a trojan file.

As one can imagine, I have had to prematurely restart and shutdown a few times with these problems, and after I let it go through the diskscan it does when it is improperly shutdown, it says that there was an unrecoverable error: ../local settings/temp/werf6.tmp is missing, another allocation file had to be truncated or something, too - I didn't have enought time to write it all down.

If I spend some time on it I will also get a blue screen that says there was a system error and shut down to protect the system, from here it will reboot after several seconds.

I use Norton AV and at first it would detect a virus and some additional risks, delete the virus and then I would manually delete the others, it hasn't found anything in safe mode and I haven't been able to finish a scan in normal mode, as the IE box piles up and eventually bogs everything down.

Thats all I can think of right now that is going on on my system, I really hope someone can help me through this one, Im at a loss.

Thanks.

P.S. Because I know it will be bought up, I shut down system restore before doing all of this