Switching to Firefox is very easy and painless. The download is very small and when you install Firefox it will ask if you want to import your favorites. Select yes and it will bring all of your favorites over so that you can begin surfing right away. You can continue to use whatever browser you were using before too so if you don't like using firefox for any reason, you still have your old way of doing things. If you are interested in trying Firefox then you can download it here. There is also a link that talks about switching from Internet Explorer to Firefox. Check it out.
As far as cleaning up viruses and spyware that are already on your computer, you can do that for free. Do you have an anti-virus program? If so, make sure it is updated and then run a scan. If should find any viruses and offer ways to clean them or delete them. If you do not have an anti-virus program then a good free one is called AVG. You can get it here:
For cleaning up spyware, you just need another free program or two. The two that I really like are Ad Aware and Spybot Search and Destroy. They are both free. You run then and they will find spyware on your system. Just like with the anti-virus programs, make sure these are up to date. Each program has an "update" button which makes it easy. Once the programs run and it gives you the results, you will want to select them and remove them. I run these programs weekly.
You can get Ad Aware here:
and Spybot Search and Destroy here:.