This message can be caused by a few different pieces of software.
This problem could be due to a defect in the uninstaller of Norton Antivirus.
The uninstaller fails to cleanly remove some components and as a result, leaves your Windows Media Center edition in a bad state. To fix the problem you can either:
a) Reinstall Norton Antivirus.
b) Close Media Center
c) Reinstall Windows Media Center edition
d) Contact Symantec and complain about this problem to get them to acknowledge the problem and fix their product.

It can also be caused by card reader software.
It runs on startup and is a pretty much useless process.

Initially you should test to see if it is causing you problems.

Run msconfig and if it appears in your startup list disable it and restart

if that solves your problem then delete dit.exe from your windows folder (you can also get rid of dit.dll, dit.ini and ditxp.exe)

You should now do a registry sweep to get rid of any dit.exe entries
I Hope this Helps