BIG PROBLEMS!

My computer will not let me search, run a virus or spyware scan. I noticed after I stop
typing some of the letters slowly show up.
None of the searches can be displayed,including
my email page.
This all started on internet explorer,and now it is in firefox.I DON’T KNOW HOW TO FIX THIS ONE!Please if you know of anything I can do please let me know. I would really appreciate
it.
Hope I can come back to check for answers,
the only way I could get to this site today is using Windows Update. Thank You Jazznanny