Firefox Portable

Cant seem to get it to install. "Download Error"
Isnt there a work around for this?
http://toolbar.google.com/firefox/extensions/toolbar/google-toolbar.xpi

Hey,after updating to Portable firefox 1.5 i have a grey area below the status bar of perhaps 2cm or 1 inch or 4 lines with nothin in it than grey, if i switch of the status bar the grey area stays there and "steals" approx. 10% of my screenview :( GreetsS.