WER is Windows Error Reporting. It's enabled by default in Windows 7, Vista, and, yes, even XP.
Turning it off works the same as in Vista: Disable Error Reporting in Windows Vista
Whenever a program hangs or crashes occurs, Vista is able to automatically send relevant information about the failure to Microsoft using Windows Error Reporting (WER), have this information analyzed and obtain a solution to the problem if one exists. In case you are testing beta versions of applications, you might encounter this situation many times. Some times the Error Reporting can be annoying, but it can be turned off using Group Policy Editor.
I suspect these error reports are a reason for the network activity. If you've accumulated 89 GB of them, you've hardware or application problems.
Windows 7 Media Center has been working like a champ for me. No crashes even when using three tuners to record.
It's a beta. There will be problems for some.