Can't download files

[smurfchops]

Since having a new hard drive in my windows 7 I can't download files. I don't have Adobe Acrobat etc which I think some programmes need. I get a window that says 'this programme has know compatability issues' and then the screen freezes. What should I download (free if possible) to help me get into files? I am not technical as you all know so easy answers please.

[smurfchops]

By the way I use Mozilla m Firefox most of the time. I think someone once gave me a download to use with Mozilla to open files and now I can't find the question or answer ! Also my keys are still jumping around the page, if anyone can help with this I would be grateful. Half the word I am typing flys up to another part of the page it is driving me mad .... I am taking care not to touch the touch pad as I type by the way ... Thanks all