Precision 650 turned off Hyperthreading (4Cpu-2Cpu)

[Guest]

Archived from groups: alt.sys.pc-clone.dell (More info?)

brand new Dell Precision 650, preloaded with XP Pro SP1

today while browsing google (firewall enabled and all MS updates applied)
the service Wmiapsrv.exe suddenly started eating lots of resources, so I
rebooted system

when it came back up, hyperthreading mode in task manager had been turned
off, instead of showing 4 CPU's, it now shows 2 CPU's

anyone venture a guess why or what occurred?
virusscan is clean, so is the event log

 

[Guest]

Archived from groups: alt.sys.pc-clone.dell (More info?)

just in case, I do know how to re-enable it in bios, but wondered why it
changed all of a sudden or if this is a known issue