I should have added these 2 excellent FREE anti-virus programs. They are free to download as well as free to use. There really is no need to spend a lot of money for good anti-virus software. I have personally seen AVG find something which an expensive program did not find.
These files are quite large and you can download them if you are on a modem but it will take some time.
AVG is an anti-virus program, download it and install it. It updates sometimes on a daily basis.
It will also daily scan your hard drive automatically for problems. It will monitor incoming and outgoing emails if you use Outlook or Outlook Express.
http://free.grisoft.com/doc/avg-anti-vi ... /us/tpl/v5
AVG also lets you download a free "Root kit cleaner".
http://free.grisoft.com/doc/39798/lng/us/tpl/v5
The other free program is AVAST, it is free to download and to use. This program needs to be manually run to do a complete scan of your hard drive. To use it for longer than 30 days it requires you to register, which is free also.
Then it is yours to use for about 14 - 16 months and after that it just requires you to re-register it. It automatically updates frequently. It also monitors incoming and outgoing emails, I know it works with Outlook Express. Others I do not know about.
http://www.avast.com/eng/download-avast-home.html
You can also download a free virus cleaner here if you suspect that you have a virus infection.
http://www.avast.com/eng/down_cleaner.html
This is for any program:
Read the instructions that come with it and read the "HELP" section which comes with EVERY program.