XP keeps crashing and running very slow

Hello all, I'm having serious problems with XP home pc. In the event viewer system I keep getting two error messages:

Event Type: Error
Event Source: Service Control Manager
Event Category: None
Event ID: 7022
Date: 8/10/2008
Time: 12:08:22
User: N/A
Computer: HOME-TUM01T7ZLL
Description:
The KService service hung on starting.

Event Type: Error
Event Source: Service Control Manager
Event Category: None
Event ID: 7023
Date: 8/10/2008
Time: 12:07:13
User: N/A
Computer: HOME-TUM01T7ZLL
Description:
The IPSEC Services service terminated with the following error:
The authentication service is unknown.


Can anyone please help?

Possibly related :

http://www.opinionatedgeek.com/Blog/blogentry=000175/BlogEntry.aspx

http://www.pcdoctor-guide.com/wordpress/?p=2452

Apparently a possibly insidious piece of software that isn't easy to uninstall. See the second link above for some advice and use at your own risk.

The IPSEC Service may be damaged by the other - check your Services in Control Panel and see if you can start it.

http://www.theeldergeek.com/ipsec_services.htm