Cannot uninstall Comodo Internet Security (Windows XP, SP3)

I’ve installed Norton Internet Security 2011, which is working correctly but am having problems un-installing Comodo Internet Security (free edition). I did a search and couldn’t find anything regarding this, I found a link to a Comodo clean up tool but I’m assuming this to do with cleaning up after the program has uninstalled (such as removing registry entries etc.).

This is the error message I’m receiving:

“A network error occurred while attempting to read from the file:

I have restarted the PC a few times, but it still displaying the same error message. I also tried to uninstall in safe mode but it couldn’t open windows installer as this option isn’t available in safe mode.

Edit: Had a look in program files and Comodo folder is 457KB, so I’m guessing it might have uninstalled but not successfully, which is why it’s giving the error message. Will running the Comodo clean up tool work?