Can't update, can't go back to V4, computer hanging

Hi, Anybody know what's wrong here.
I've written before about this. I had, by a friends mistake, V5 Windows Update installed. I was told there is no way to uninstall it.

I had to manually go to the v4 Windowsupdate and it worked for some time.
Now I am redirected to v5 anyway, whatever I do.

The problem is that v5 never stops scanning my computer for updates.
Last time I let it stand there. After 9 hours it was still scanning. Cant shut down IExplorer, can't do anything. Have to pull the plug every time and run a 50 min's Chkdsk. What can I do about this? Can i Re-install that crappy V5 update and at least try to make that work?

Don't tell me to re-install Windows. I am on a travel and can't do that because I don't have a pile of all the CD's with me to re-install everything. I am also only connected via a modem for at least another 6 weeks here.

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Working hard...