If you install or remove a program on Windows Server 2003, or Windows Small Business Server 2003, restarting your computer may result in the subject behavior. Restarting the Workstation service generates:

Error 1364: A specified authentication package is unknown.

This problem will occur if the progam that you installed or remove deleted the Authentication Packages Value Name, a REG_MULT_SZ data type, at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa. The data value of the Authentication Packages Value Name should be msv1_0.

To resolve this issue:

1. Copy / Paste the following into Notepad.exe.

REGEDIT4                              \[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\]                              "Authentication Packages"=hex(7):6d,73,76,31,5f,30,00,00
2. Save the file as LsaAP.txt.

3. Rename the LsaAP.txt file to LsaAP.reg.

4. Right-click the LsaAP.reg file and press Merge, you run REGEDIT /S LsaAP.reg.

5. Shutdown and restart your server.