recently my previous hard disk failed and i replaced it with a new one and i installed windows 2000 pro service pack 4,
i retrived my data from the faulty drive and was doing good till i start connecting to the net;

now i get the error svchost.exe the referenced memory could not be accessed.

i searched and seen many articles explaining what the cause might be , some suggest a virus or worm,
others may be installing the microsoft security patch or downloading the norton tools for fixing the blaster
or welch worm might fix the problem, the microsoft web site suggests editing the registry might solve the problem.

I have a theory how this might have been caused
I first copied the data from the faulty drive on my friends pc; maybe i got the virus from there and i connected the previous
drive to my pc at home so may be if it's a virus thats where i got it from.

Now i have the following symptoms

when i connect to the internet the error message appears and i closed the svchost.exe
no system crash but various odd things showed up i could not copy/paste, move files, and cliking on a URL and
open in a new window could not work, add/remove programs in control panel looked funny, Norton Anti Virus 2004 was disabled
could not launch it again even after i rebotted, the regedit.exe and regedt32.exe don't work till now ,wasn't able to
disconnect i had to manually remove the phone line or restart the computer.windows update could not work....

After the first encounter with the error message i rebooted the computer and start connecting again then i saw that
the domain field in the connection settings was empty i retyped the server and got connected again boom!!! i see the error
message again now all the symptoms show up again

if i don't connect some of the problems still persist as Norton couldn't start, regedit and regedt32 don't work

In the Middle of connection i see the error message that says internet explorer generated errors and stuff
then when i say don't send a new IE window is launched

Then i downloaded Windows2000-KB823980 security patch as i start to excute the program it exits as soon as it starts
then i downloaded windows2000-KB833330 and i excute it it starts and suddenly exits.

now i see a new message that says your registry size is low increase the registry size it was 18Mb now i made it to 20MB
still no change

I really tried everything;

-Editing the registry is impossible since regedt32 and regedit don't work
maybe i was thinking of writing a program to modify the regstry keys but i am not sure if the suggestion really works,
or i might be messing up the registry by the program i write (VC6)

-i downloaded the norton tools and scanned for the blaster and welch still no infection.

-i unistalled and reinstalled the Norton Anti Virus still no change Norton could not be Activated and Excuted

What is really happening ?? Does any one has any Ideas ? Pls Help