His name is CPC2004.
And until he gets here maybe I can help.
He would first ask if you have more then 1 minidump you can send? And if you can get some that are more current. This one is from over 10 days old. So if you can, attach up to 4 or 6 current dumps.
Second, your bugcheck is 0x1000008E. You can research this on google if you like, tons of stuff there. I don't have time to look it up just now.
You say it crashes only when you backup? How do you backup? In that case, you should probably try updating any drivers relating to that system. Such as hardware, or updating your backup software itself.
Next, in your System log, you should have events 1001 and 1003. Find your current ones and post the details here as well. To get to the log, right-click My Computer and choose Manage. The event logs are in there.
Good luck!