Is your computer running slowly? Are you getting random errors? Pop-up windows when you're not even using the Internet? If so, you probably have a virus, worm or spyware program infecting your system. Unfortunately, this is an incredibly common problem for many people. This isn't likely going to be a quick fix, but using the directions below will probably help you get your system working better again.
I'm not sure what operating system you're running, but if it's Windows XP, you may want to consider installing the Service Pack 2 (SP2) patch if you haven't done so already. I've not had any trouble with it myself, but I've heard a few horror stories so proceed cautiously and make a backup of anything important on your computer. After having said all that, I should mention that I've installed SP2 on five computers without encountering any troubles. If you want to proceed with the SP2 upgrade, Microsoft highly recommends that you remove any viruses, spyware or worms that may be on your system FIRST. In other words, do the following steps first and then come back and install SP2. Once SP2 is installed, you can disable or uninstall the ZoneAlarm firewall since SP2 has a built-in firewall.
Here are the steps you should follow to fix your computer problems:
Step 1: Install a firewall that will prevent re-infection:
When you install, make sure you check the item "ZoneAlarm" (Free) and not "ZoneAlarm Pro". It's a completely free Firewall that works great. Once it's installed and running, it will notify you of any applications on your computer that are attempting to connect to the Internet. You will need to allow legitimate applications to connect but you should deny access to applications that don't look familiar. All unsolicited incoming connections will be blocked by default (which is a good thing).
Step 2: Make sure you're running anti-virus software and it's up-to-date.
If you don't have any anti-virus software, you can get free AVG software stuff from Grisoft.com:
Choose "AVG Anti-Virus Free Edition download" or try this direct link.
This software is free including indefinitely free updates and it seems to work great. Be sure to perform a full system scan once the software is installed.
Note: If you currently have a virus on your computer, it may be difficult to remove it. You may have to actually purchase a physical copy of Grisoft's Anti-virus, Norton Anti-virus or McAfee Anti-virus so that you can boot from the CD and remove the virus before it loads into memory. (Be sure to power your computer down before booting from the CD!)
Step 3: Use a spyware removal tool to get rid of any bad stuff:
It is usually recommended that you also use "Spybot Search and Destroy" (also free) if you're having trouble with spyware/adware:
If that still doesn't fix the problem (although, it probably will), you can also run "CWShredder" (CoolWebSearch remover):
In the past, I would declare that the above steps should help you remove most any nasties on your system. Unfortunately, that's not the case anymore. According to an article I read recently, not even two popular anti-adware programs used together can remove 100% of the spyware/adware that is circulating. The article claims that the best two applications are Giant AntiSpyware (which is now owned by Microsoft and has been re-released as a free beta version from Microsoft) and Webroot Spy Sweeper (not free, but they have a free trial). They recommend that you run both of these plus "CWShredder" (listed above) to take care of most of the problems. One nice thing about the Microsoft product is that it continuously runs in the background and prevents new adware/spyware from being installed or from changing key settings on your system.
If you still seem to be having problems, I recommend that you look in the "Add or Remove Programs" item in the Windows Control Panel. I recommend you remove any screen savers, games or utilities that could possibly be causing problems. You can always re-install them later if necessary.
Step 4 (optional): Change to a more secure web browser:
If you are sick of pop-ups during your web browsing experiences or if you are concerned about the insecurity of Microsoft's Internet Explorer, I highly recommend you try Mozilla Firefox. I've been using it for quite awhile and have been very impressed with it.