I have Ad-Aware and Spybot seek and destroy. They work well, but my computer still runs pretty slow, like it’s got some viruses or something else going on…. Can’t afford to buy any programs. 
Also, I only use firefox, I don’t use Internet Explorer at all.
1.Anti-virus >
AVG: http://free.grisoft.com/doc/5390/lng/us/tpl/v5#avg-anti-virus-free
Avast: http://avast.com/eng/download-avast-home.html
AntiVir: http://www.free-av.com/down/windows/anti...
AOL Active Virus Shield :http://www.activevirusshield.com/antivirus/freeav/index.adp
2.Spyware/Adware Protection > (AdAware and SpyBot are very good)
Spyware Terminator: http://www.spywareterminator.com/
Windows Defender (only for genuine Windows XP): http://www.microsoft.com/downloads/details.aspx?FamilyID=435bfce7-da2b-4a6a-afa4-f7f14e605a0d&displaylang=en
Super Anti-Spyware Free Edition: http://www.download.com/superantispyware...
3.Firewall >
Comodo Personal Firewall: http://www.personalfirewall.comodo.com/
ZoneAlarm: http://www.majorgeeks.com/ZoneAlarm_Free_d388.html
You may also require temporary files and other trash cleaners. Get both these freeware, and run them(both ‘Cleaner’ and ‘Issues’ section of CCleaner) to remove all crap.
CCleaner (9): http://www.ccleaner.com/
Disk Cleaner (7.5): http://www.diskcleaner.nl/download.php
PCSleek Free Error Cleaner: http://www.pcsleek.com/
Here are some must-read security tips:
1.Never use more than one anti-virus or firewall. There is a good possibility that they will fight each other. However, you can use as many anti-spywares as you wish(use real protection of only one).
2.Always keep the real time scanning/resident shield of your anti-virus and any one of your anti-spyware active.
3.Keep all your security software updated, and scan your computer for spyware every 1 week and for viruses every 2 weeks.
runs slow or just internet browsing is slow?
majorgeeks.com lists a bunch of freedownloads
Use both.
1. Scan for virus and remove (free online scan, no download) with BitDefender.
http://www.bitdefender.com/site/home/
2. Scan for trojans and spyware and remove (free online scan, no download) with Ewido.
http://www.ewido.net/en/
Adaware and Spybot are both anti-spyware apps. You need an anti-virus too!
Then U scan ur harddisk with the help of free online virus scan software..
Try formatting your computer to get rid of all the files. That will give you a clean hard drive with alot of space.
After you reinstall windows just install any simple antivirus program, e.g. Avast! you don’t need to install so many stuffs like firewall & privacy & spyware stuff, coz it will take up alot of space and resources(i’m guessing you are using a lousy com). Juz don’t visit porn sites and virus and hacking and free downloads stuff and you will be allrite.
For search engines use a reputable name such as Google and Yahoo.
Just because your pc is running slow doesn’t mean you got virus, trojans, etc. Could just mean your running to many programs upon your computer startup. To know if you are count how many icons are next to your clock (bottom right of screen).
I’ve used AVG for close to 2 years now and never had a problem. Been fixing computers for 7 years and after trying them all I wouldnt use anything but AVG for antivirus program. If you need me to help you speed up your PC add me to yahoo messenger misterb_1972@yahoo.com. Here’s AVG free link: http://free.grisoft.com/freeweb.php/doc/5390/lng/us/tpl/v5#avg-anti-virus-free Go down to about middle of page and click the orange file link: avg75free_432a904.exe.
try AVG AntiVirus
try this online scan
http://www.housecall.trendmicro.com
having your pc slowing down doesn’t mean you have a virus, could be several things, may need to run disk cleanup, defrag (start,programs, accessories, system tools)
could be your low or getting low on memeory, have too many programs running at start up
here are downloads of the most popular spyware removers:
http://www.2-spyware.com/anti-spyware
btw don’t run spybot and ad-aware at the same time, they may try to stop each other and this might be a reason why your computer runs slowly.
stop using windows and all proprietary software. mandriva is a good choice. You will no longer have any problems with viruses, malware, etc.
avg is the best choice for a free antivirus software
There are a number of antivirus and anti spyware in the market. Some are free and some are to be purchased. Please visit the following site and select a suitable free antivirus.
http://tinyurl.com/ymctqq
You can visit the following site , if you want a more effective antivirus . You have to pay for it!
http://tinyurl.com/ykzjyp
You also try to select and install a suitable anti spyware from the following link to protect the Pc against spyware attacks.
http://tinyurl.com/ygvyzh
most virus are spread through IE. IE is not a safe browser. you should use a more secure browser to protect your PC from virus.
i recommand you to use firefox with Google toolbar. firefox can block any any popup and disable any virus and adware, spyware on webpage, so, firefox is much safer than IE browser. as you know, most of virus spread throught internet and webpage.
besides, firefox is much smaller than IE, so it run faster than IE.
download firefox for free, Just have a try:
http://www.toolforyou.net/firefox/
Good Luck, Merry Xmas !!!