as far as compression they are equal. 7-zip will make some files smaller than winrar and visa versa. however it is a fact that on some large files 7-zip will corrupt them while compressing them. i strongly recommend steering clear of 7-zip, even though it is free. by the way yell in your post is not going to make me change my opinion.

Yes. If it's not working, something is wrong.Doesn't the OS have a built-in zip file extractor?
I don't have any other files to try , but I still need to open these in order to install them . Sorry for the confusion , I did say I was an idiot !

Thanks so much , it's only easy when you know how ! I've installed them , thanks to you . A big thank you to all who tried to help . I'm very grateful .Bills, you have to load the ABR file from within PS.
Don't know what version you are using but in CS4 you select the brush tool. then from the brush on the toolbar select the down arrow, then the arrow pointing right, then 'preset manager', then select 'brushes' from the drop down, then 'load' and point to your ABR files.
Easy!