http://forums.arcgis.com/threads/312-Beta-10-Lock-Files [ArcGIS 10: Lock Files][1] According to the above post the only way to delete these sr.lock files is to completely exit all ArcGIS programs. When attempting copy & paste of a recently used shape file (with corresponding mxd closed) this error pops up ![sr lock error][2] It will paste a portion of the shape files, but not all of them. I have both service packs 1 and 2 installed. [1]: http://forums.arcgis.com/threads/312-Beta-10-Lock-Files [2]: https://i.sstatic.net/NX9Go.png