This might probably interest someone having similar problems. I followed the advice given above and re-installed Internet Explore 8 after which I took out FireFox - everything suddenly started working again like magic. This event was not directly related to CCleaner of course but some of the initial problems first became aparent when I tried to update CCleaner and it wouldn't: neither would any of the links on the CCleaner page work (amongst some others, as it ultimately transpired). Hope this might help others who try the same thing I did. My grateful thanks to all who answered my appeal for help. Peter.