For what it's worth, I have been using CCleaner now for about 5 or 6 years, running it every day and sometimes twice. I also run AVG PC Tuneup 2011 daily (AVG paid version). Yes, these programs definitely clean it all up -- they do what they're supposed to. However, they have not solved the problem of the internet failing. I guess I will follow the advice on this thread and swap to Windows 7. Thanks guys.
Also, for what it's worth, I have nothing much running on this computer except for what is necessary for WD to operate. That includes TeamViewer and StartWatch. I note that others on this forum also use these programs and, as they are not having problems, assume they are not the source of my troubles. Other than these programs, I also have Skype loaded, but never use it, Solid Capture, a Logitec program to run the WD webcam, and a DVD burn program. So, if it's a software problem, I feel as if I'm left with Windows XP Professional as being the culprit as all hardware has been either replaced or checked somehow or other.
One thought has arisen though. Does anyone think the running CCleaner and AVG Tuneup daily or more often could have screwed up XP? Sorry Niko, but reading the thread you suggested to look at in relation to registry cleaners does not bag them to my mind. Have I missed something?
Cheers,
Rick