CPU maxing out running explorer.exe

Hello

We have a strange problem with an XP Pro laptop running offline files. For some time the user has complained that the pc is extremely slow and it is extremely hot.
When we checked it we found offline files doesn't run at all and that there are two processes running constantly, explorer.exe and mobsync.exe. This means that the cpu is at 100% all the time. There are actually 2 instances of mobsync.exe, one of which remains at 0% while the other hovers around 50% cpu time.

Can anyone shed any light on what might be happening here. It will be a big job to blitz the pc and start again so any help resolving this an easier way will be appreciated.

Thanks

 

===F.Y.I.===
Additional nfo:[if not home page]....still an IE option for offline web content, but user may not have homepage set to automatcally syncronize but has used this function for something else, possibly downloaded a website for offline viewing.
See...

Process File: mobsync or mobsync.exe
Process Name: Microsoft Synchronization Manager
Description: Application associated with Internet Explorer and used to update the network copy of materials that were edited offline, such as documents, calendars, and e-mail messages.
Company: Microsoft Corp.

"This program, which is part of Internet Explorer 5.x/6, runs in the background when you are using the "View pages offline" feature of Internet Explorer, and you have set parameters for when your pages should be automatically synchronised, or you decide to manually synchronise your offline content with the web through the
"Start>Programs>Accessories>Synchronize" function.

This program will also run if you are doing development using Microsoft SQL 7 and using SQL 7 replication. "