Question : XP runs slow error 0XC000005e,The Security System detected an attempted downgrade attack for server

Application Log:
Source: Userenv
Description: Windows connot determin the user or computer name. (The RPC
server is unavailable). Group Policy processing aborted.

Then sequentially from the System Log:
a series of LSASRV (SPNEG0) events including

"The Security System detected an attempted downgrade attack for server
cifs/servername. The failure code from authentication protocol Kerberos was
"There are currently no logon servers available to service the logon
request. (0xc000005e)".

"The Security System could not establish a secured connection with the
server cifs/servername. No authentication protocol was available."

The Security System detected an attempted downgrade attack for server
cifs/logonserver. The failure code from authentication protocol Kerberos
was "There are currently no logon servers available to service the logon
request. (0xc000005e)".

The Security System could not establish a secured connection with the server
cifs/logonserver. No authentication protocol was available.

The Security System detected an attempted downgrade attack for server
cifs/servername. The failure code from authentication protocol Kerberos was
"There are currently no logon servers available to service the logon
request.
(0xc000005e)".

Answer : XP runs slow error 0XC000005e,The Security System detected an attempted downgrade attack for server

Turned out that the PC a DELL OPTIPLEX 960 had its SATA setting in the BIOS on RAID, I turned it back to ATA and the problem disappeared.  The BIOS is password protected so why it would suddenly flip to RAID is beyond me. I should probably check with DELL for a BIOS update.