Unfortunately the results you named have already gone from the database.
First, take a look if the file h1_1323.5_S5R1__660_S5R1a_1_0 is actually there (in BOINC/projects/einstein.phys.uwm.edu/).
If it is, one thing I would check is the permissions of the BOINC directory and the project directories, and manually try to fix them if the user BOINC is running as is missing e.g. the permissions to create or delete a file.
You could also uninstall BOINC, then make sure to delete everything that's left in the BOINC directory (including all subdirectories) with the possible exception of the account*.xml files (so you don't have to attach again), and then do a fresh BOINC installation. This is the most drastic way, and you will lose all work that is currently in progress and have to download all datafiles again.
If the file is not there, you can either safely ignore the error, create a dummy file for BOINC to delete, or start to mess around with the client_state.xml (which I would definitely not recommend at all).
BM

Couldn't delete file...
)
I'm kind of clueless. Are you sharing the drive BOINC is installed in, or any directories ("Program Files") on the network?
BM
BM
Brian, The advice you are
)
Brian,
The advice you are getting here seems sound. I am afraid that I don't have anything to add to it. I am unfortunately more of an expert on the Linux/Unix/Backend side of things than on Windows and its issues.
But I wanted to applaud you for sticking with this. I hope you get these problems sorted out and can get back to crunching for us again!
Bruce