Hi there,
I have worrying problem. Whenever I power on my machine, a light blue screen appears before loading windows. It then requests scan disk within a specified period but also requests that I press any key to load without scan disk.

My other machines on the network behaved this way sometimes ago and allover a sudden the network was so slow. I called some technical experts who claimed it was a virus. True I found funny files by the name adware.gator (3 of them) which I could not delete. I formatted all the systems since internet sharing through one machine was impossible.

What's causing the blue screen? Thats where I began the other time. I believe its not a virus because I have updated norton 2003. Are the system files corrupted by any chance? How can I help this? Will I have to reload and reformat winxp?

I'm in the process of solving the same problem for a customer. I don't think it's a virus or Trojan; I'm 99% sure it's one or more corrupted files connected with the NT file system (NTFS). She has a bootleg install of XP Pro (she didn't know), so I had her buy a legal OEM copy on Ebay. As soon as I fix things, I'll report back.

Her system has been like this for months, with no other obvious problems, so I'm not too worried, but we gotta fix it soon.

Would you therefore suggest that I return the machine to the network? By the way, the screen of that machine keeps on flickering and looks like its shaking. Though at times its quite stable. Can you explain the erratic behaviour of the screen also

I think a network connection is OK. It has been in my case, anyway.

"Screen shaking" and flickering is usually caused by outside magnetic fields, usually AC transformers. Typical sources include the ballast in a flourescent desk lamp, "wall wart" power cubes, small fans, and AC-operated desk clocks or radios. Many of these devices produce magnetic fields even when turned off; large-screen monitors are more susceptible to this.

The flickering was solved. I think the monitor had a problem. I also noticed the power source if unstable could cause the flickering and shaking

download a program called ad-aware6 it will scan your computer for any or most known spyware which can cause your computer to run slow and as to remove it boot you computer in safe-mode and it should let you delete it because in safe-mode the program hasn't started only the files used to run your OS have started.

I promised that I would post when I found the cause of this. I have found it: a corrupted Windows Registry.

This can be easily confirmed by booting into Safe Mode. After running ChkDsk and booting fully into Safe Mode, reboot. If ChkDsk does not run on the next boot, the Registry problem is confirmed.

In my case, the WinXP install with problems was bootleg. I backed up the data and did an install-from-scratch with an OEM copy of WinXP Pro ($130 on eBay). The customer is happy; she didn't know her original XP Pro was illegal in the first place.

I used this Microsoft article for reference: http://support.microsoft.com/?kbid=316506