Our old favorite AdAware from Lavasoft. (Don't get tricked into getting or buying something named close like AdWare. This is not what you want). The current Free version is AdAware 2008. Click here and you should see:
Click on the Download Now or the Icon next to it and the download process should begin. It should download as filename aaw2008.exe. Save it in your favorite download location. Just make note of where you saved the file! This may be the Desktop, a special folder you use named Downloads, or the My Documents folder. Again, if you are using dial-up access to the internet get this file from another system with High Speed access. Twenty three meg is too much for dial-up.
Please understand some of the programs are small (less than 1 meg) and can be downloaded fairly easily from a dialup connection. Some are large and pretty much require a fast connection (DSL, cable, or direct connect to the internet). If you have dialup buy a USB memory stick (1 Gig or more) and get familiar with its use. When you plug it in it becomes just another Hard Disk Drive (logically) to Windows. It will show up as an additional drive in your My Computer icon. You can write to that drive, create personal folders on it and write to them, then take it to another computer, plug it in and read the data you wrote before. You can take this memory stick to a library, coffee shop, hot spot for a laptop, or just a friend's house that has high speed internet access. Do your downloads, copy them to your memory stick then take them home for use on your dialup computer. In our shop we have numerous computers available for open use that may be used for big downloads by customers.
After the file is downloaded go to where you downloaded it and double click on the file. You should see this:
Choose to Run the file, choose English, Next on the welcome screen then select "I accept... on the license info. Select "Anyone who uses this computer" on the next screen then choose "Standard Installation" then Next then Next again at the folder selection screen. After the install completes select the "Use Free" button. Next it should get any updates and then the program should start. At the initial status page click the "Update" button to be sure it is current (mine did not automatically update at install and I was over a month out of date). Here is a picture of the status screen after I updated it. If yours is current you can click on "Scan Now" and it should begin. I choose Full Scan but if you are just doing a scan for prevention
Here is an example of a REALLY bad guy on my system after the scan finishes.
Make sure what AdAware finds bad has a check mark next to it then click on the Remove button. This will remove the Critical Objects (see the tabs at the top). Next select the Privacy Objects (cookies) tab and check all then Remove again. I got rid of 3 critical objects and 8 cookies. These critical objects were missed by my regular AVG monitoring. Sometimes they slip by!