Are all applications freezing up or only one or a few? Has there been new software or hardware added since the problem started? For example, did the problems start when DSL was added?

Answer luis pr Qusetions then see below.

Make & model of computer?

What operating System Vista or XP?

Laptop or desk top?

Follow directions and run these 2 programs.

Download ATF Cleaner by Atribune to your Desktop.

Note: Vista users must use Run As Administrator
 Under Main: Select Files to Delete choose: Select All.
 Click the Empty Selected button.
 If you use Firefox browser click Firefox at the top and choose: Select All
 Click the Empty Selected button.
If you would like to keep your saved passwords click No at the prompt.
 If you use Opera browser click Opera at the top and choose: Select All
 Click the Empty Selected button.
If you would like to keep your saved passwords click No at the prompt.
 Click Exit on the Main menu to close the program.

Please download Malwarebytes' Anti-Malware to your desktop. Click here
* Double-click mbam-setup.exe and follow the prompts to install the program.
* At the end, be sure a checkmark is placed next to Update Malwarebytes' Anti-Malware and Launch Malwarebytes' Anti-Malware, then click Finish.
* If an update is found, it will download and install the latest version.
* Once the program has loaded, select Perform full scan, then click Scan.
* When the scan is complete, click OK, then Show Results to view the results.
* Be sure that everything is checked, and click Remove Selected.
 The log is automatically saved by MBAM and can be viewed by clicking the Logs tab in MBAM.
The log can also be found here: C:\Documents and Settings\Username\Application Data\Malwarebytes\Malwarebytes' Anti-Malware\Logs\log-date.txt

 Copy and Paste the entire report in your next reply.

I could have got a virus since DSL, I don't know. Once it freezes I have to unplug the system to get it going again. I have a 2 yr old Dell XP desktop. I haven't added any new programs that I know of. I haven't did the cleanup yet, I am so afraid of downloading anything or adding programs.

You need to run the programs to start the process, or take it in for repair.

A lot of folks in your shoes don't have the ability to download these programs because the pc is to far gone, consider yourself lucky you can at least start the process.

the 2 programs zep has given you are excellent programs and you need not be worried about installing them, they are very beneficial and you will be able to use them to help keep your pc clean in the future.
It is good to be cautious but these are definitely good safe helpful programs.

You should also try doing an online scan since your AVG may be compromised.
FREE Online Virus Scan