If you receive a blue screen when you try to access a network shared drive after upgrading to Service Pack 2 in Windows XP, try the following...in the following order. Only move to the next step if the previous step didn't work.

The blue screen may say 0x50, PAGE_FAULT_IN_NONPAGED_AREA

1) Remove (unmap) any network drives you have and remap them.

2) Search for mrxdav.sys and delete all entries that show up and reboot.

3) Scan your system for spyware. I suggest either using Ad-Aware or Spybot Search & Destroy. Have the spyware scanner delete everything that shows up.

Most of the time, the file should be 181,248 bytes.

Microsoft also has this Knowledge Base article, but you have to call Microsoft for the fix:

http://support.microsoft.com/Default.aspx?kbid=832143

It says this only fixed the problem if you are opening a network share by using Web Distributed Authoring and Versioning (WebDAV).