1. Run defragmenter
2. Install CCleaner and use it to delete all temp files, remove automated startups of useless programs and fix your registry
3. Install JV16 powertools and fix your registry again
4. get f-Secure antivirus for workstations
5. get adsl modem that can do NAT and after that you dont need firewall in you computer IF you are used to use your brains when you surf in internet

I don't know are you left or right handed
6. DO NOT install useless software just to see what it is