Yes, it could be a power issue, though I doubt it since it only happens when you are the internet. It may be Internet Explorer causing the problem if it only happens when you are on the internet, such as downloading something. Try first going to Help and Support on your start menu and do all of the updates for Windows XP and see if that doesn't solve the problem. If it doesn't, if possible, try to download Mozilla Firefox from http://www.Mozilla.org. If you get that downloaded, install it and see if Firefox causes your PC to crash. If you have done an install of Windows, you may have to do it again and make sure that you completely wipe the hard drive. Run the Windows installer, delete the partition, then format the hard drive. Then complete the install. You will know that you have a completely fresh install after that.
