I had the same problem with my recently purchased PC with XP Media Center. I
set up 3 user profiles but only one could access Internet Explorer at a time.
My fix (identified on another site) was to disable the McAfee AntiPhishing
Filter (Browser Helper; mcapfbho.dll). This can be accessed by going to IE
Tools > Internet Options > Programs > Manage Add-Ons > Select under "Show":
Add-ins currently loaded in IE > Select the above filter and "Disable". This
will need to be done in each user account. I can now access Internet
Explorer in all 3 accounts simultaneously.

"Gary" wrote:

> I just bought a new PC with XP media centre
> I have set up 2 user profiles. The primary one is fine but the secondary
> for another user keeps giving the following error message when I click My
> Computer or try to access explorer:
>
> Microsoft Visual C++ Runtime Library
> Runtime Error
> Program: C:\Windows\Explore.Exe
> This application has requested the Runtime to terminate it in an unusual
> way. Please contact the applications support team for more information.
>
> When I click or try to access IE i get this message:
>
> Microsoft Visual C++ Runtime Library
> Runtime Error
> Program: C:\Program Files \ Internet Explorer| Iexplore.exe
> This application has requested the Runtime to terminate it in an unusual
> way. Please contact the applications support team for more information.
>
> Can someone please help
>
> Thanks
> Gary
>