It is critical to the proper operation of your computer and Internet surfing experience, to fully protect your computer. It's quite simple, but make sure you do -at least- the following:
1) Make sure your Windows software is up to date. Updates are free. To get the updates, start Internet Explorer and connect to the Internet. Click on Tools, then Windows Update. Follow the web site instructions. You can set this to auto-update so you stay current.
2) Update virus definitions: you -do- have anti-virus software right? If not, get one fast. A good FREE program is called AVG and can be downloaded at http://free.grisoft.com/
Costco has Norton Internet Security which includes anti-virus, firewall and spam filter for $54. Once an anti-virus is installed, you must update it's definitions weekly to stay current. See your product's on line help for updates to see how to stay current.
3) Check for programs hiding on your computer called Ad-ware also called Spy-ware. A free utility called Spybot-Search and Destroy v1.3 will scan for them. To download it, go to www.download.com, and enter 'spybot' to search. If any of these programs exist on your PC they will use your internet connection making your experience much slower. Also, they may send some of your personal information. Best to remove them. Another one is called WebRoot SpySweeper , this is very good but costs about $24 available at Costco. Microsoft has a free one at their site called Defender.
4) Another option is to replace your current browser with a free one called Firefox. It works very well and seems to have less problems than IE.