are you on windows vista?

please try pressing the windows-key+r and enter "%temp%" (without quotes) into the open-field and click ok. then a new explorer window should pop up - delete all the contents of this folder & right-click it, go to properties and make sure that it is not write-protected.

afterwards try running the firefox setup again.

Thank you. Yes, I'm using windows. so I'm off to see what havoc I can reach. Wish me luck. And thanks, Lee.

Hey Madperson, do you mean delete any and all the items I see in the left hand side of the screen? Lee

i don't use vista myself so i cannot give you exact guidance, put in case on the left hand side is a folder tree, don't delete that! you only want to delete the content of this single folder & its usually shown in the right side of the window (see sample screenshot attached).

another thing to be sure you get the right files would be to just press ctrl+a after you've opened the %temp% command in the run dialog - then you will select all files of this folder. afterwards hit del.