It's quite an old laptop, and not approved by DELL for upgrade to '10... which may have nothing whatsoever to do with the problem you're seeing..

More ideas:
Abnormally high CPU usage from svchost.exe - Microsoft Community
Get two programs: Process Explorer, and Process Monitor. Anytime you run these, make sure you run as administrator.
Using task manager, find the PID of the task that is causing problems. Then open Process Monitor and create a filter to display only results with that PID, as well as anything else you want to specify (ex., only display read/write, etc.)
After you capture for a bit, you will have a very thorough list of everything that has happened with that PID. Make sure you are able to view two specific columns of information: TID and Duration.

At this point, I would recommend saving the Process Monitor output as a CSV file and opening it with Excel. Then you can use a few quick formulas and sorting to find which TID(s) are taking the longest. (If your not good with Excel, feel free to PM me your CSV file and I can help with this part.)

From there, you can use Process Explorer (important to run as admin) to locate the PID that is causing issues. If you double click the PID you can get more information, including a list of threads (and their corresponding TIDs) and determine what module (probably a dll file) corresponds with the problem TID. From that, you should be able to determin ewhich service specifically is causing problems, and either disable it or take whatever steps necessary to fix it."