Silly question, you are clicking on 'live' links, that is links that show up in the forum as coloured red. If you see a link like this http://www.alexander-advertising.co.uk and click on it, it will not work. It must be shewn thus:- http://www.alexander-advertising.co.uk for it to work.
The only other suggestion I can make is for you to find the 'repair' I.E. tab and run that. I believe this option is available on W98 but not on XP.
http://www.oceaneagle.fsnet.co.uk/