如何將VSS的Admin密碼重設為空白

The best place to do this, is in an empty VSS database. Save the dataum.dat file here, and get a copy of the dataum.dat file from the database where the admin password is lost. Verify that you are prompted for a password when opening VSS Admin on this database.

With a good binary data editor, like UltraEdit-32, replace the 2 bytes just before "Admin" with BC 7F, and the 2 bytes at offset +32 bytes counting from the A in Admin with 90 6E. In a database where Admin is the first entry, the (decimal) offsets are 130, 131 for the first 2 bytes, (the 'A' in Admin has offset 132), and 164, 165 for the last 2 bytes. When Admin is not the first entry (VSS saves users alphabetically), these offsets are +64 per user before Admin. You can also easily test that this is the needed change by saving um.dat before and after setting the Admin password in an empty VSS database, and (binary) compare the before and after um.dat files (this is how we found this hack anyway). Now verify with VSS admin that there is no password prompt anymore, and then copy the fixed um.dat file back to the database where the problem occurred.