I have used Panda AV on my Dell Optima running Windows (now XP) since 2007. I have decided to try Vipre instead, and had no problem loading it on my Samsung laptop with Windows 8. But when I try to run the program (from the same link) on my Dell, It is finding that I have Panda 2011 on the computer. I had uninstalled the 2013 version using Panda's uninstall program, and also did a search to find any other files associated, and deleted those, yet Vipre is still detecting the program. I also tried Cclean to try to get rid of any orphan files, but that did not clear the problem, either. I called Panda tech support and was told I would need to get a "SPECIALIST" to fully uninstall the program. Any ideas?Vipre tech support PROVIDED the following solution:
download and use this program called microsoft fixit tool to try to remove panda from the computer
you can download it from this link
http://support.microsoft.com/mats/Program_Install_and_Uninstall
Here are some instructions on running this tool:

1. Click the green Run Now button on the site linked above.
2. Run the program downloaded
3. Click the Accept button
4. Microsoft Fix It will scan the machine for Windows Install and Uninstall issues
5. Select DETECT problems and let me select the fixes to apply
6. Select Uninstalling
7. Select Panda Antivirus from the programs listed and click Next
8. Select Yes, try uninstall
9. Make sure all the Listed issues are checked and click Next
10. You will get a result status notifying you that the PROCESS succeeded.
11. Select one of the feedback options and click Next
12. Click the Close button
restart the computer

This solution worked perfectly for me! Don't forget that Windows 8 comes with it's on AV called Windows Defender. If you're going to use another AV, Windows Defender will have to be deactivated otherwise, it will CAUSE conflicts.