Adobe problems

I have the full version of Adobe Acrobat 5 on my machine in the office but I also have the Adobe 6 reader. But when I open a PDF using either IE or Firefox they use Adobe 5…I wanna use the Adobe reader 6, 5 is doing some funny things.

I tried downloading the latest version from the Adobe site but because of permissions and all that crap, I can’t install the update.

Any tips?