You may not even realize you have some of these adware/spyware/popup programs running on your computer. But if you do, you’ll notice your PC running faster after you remove them. Most of these useless programs install as part of free software or free games you download or play. Some even masquerade as useful programs. One example is PurityScan. It says it will block porn sites (which is good) but it also displays a bunch of popups and makes your PC run slow. The software links below are excellent tools (and free) to keep your PC clean of the junk and running fast.
To block popups, you can install toolbars from Google, Yahoo, or MSN. I use the Google toolbar since that is where I do my searching but they all work the same as far as blocking popups:
One more tip to keep your PC free of spyware & adware: before you install any free software or demo software, do a search on Google for the name of the software. If you see it return any results that mention the software is or includes spyware or adware, don’t install it.