I just downloaded the latest CCleaner this morning (received an update) and I was able to install it. Did you save it onto your desktop? If not, try that to see if it works.

I am not given an option to save to desktop, just Save file which comes up in the Downloads window from where other programs are normally installed.

Please read this article to see if it helps, it might give you some ideas:

http://kb.mozillazine.org/Unable_to_save_or_download_files

As an alternative, try to download from this link, it should give you an option to save to your desktop:

http://download.cnet.com/ccleaner/

Thanks silkphoenix, Lots of suggestions but I'm suffering information overload and out of my depth trying them. I will have to resort to a technician. Thanks again for your effort. Geoffjo

You can't run executable's from the Firefox download window. Right-click that download and select Open Containing Folder. Run the installer from there.

I have previously run executables from that window and this is the first time I have had this problem. I tried your method but did not get an open containing folder option to try.

Thanks anyway