So, it starts off detecting the pen and then quits after the program boots up?
Is your tablet getting power? (is the light on?). USB ports will eventually go bad, I've fixed a couple 'tablet' problems by using a powered usb hub.
If the light is on:
That sounds like maybe a driver issue to me. Uninstall it all the way and install a newer/older version. If your OS is older you may need to get an older driver. At one point I had to try three different ones to find one that worked right on my computer.
If you are on windows, you can also see exactly what is going on inside your computer with Ctrl+Alt+Delete click on the Processes tab and you can see everything that is currently running.
Open up your browser google the name of each thing that is running, you will get a definition of the program and whether you need to have it running or not. Close everything you don't need and try it.
What antivirus, operating system and tablet are you using?
Have you tried to uninstall the drivers and then reinstalled them? I doubt it would be a virus, but doing a virus scan never harms. If there is a program blocking the drivers, it's most likely the antivirus, try disable it and if that don't work then disable it during the install of the drivers.