OK... first off Dell are excellent PCs but they always put that extra partition on the system. They are slow as 'all get out' from the factory.
I have had dozens of calls from people wanting to know the exact thing you are. The reason they do it is because they back up the original factory settings on the hard drive with a special built in program they have. So, if you ever want to go back to your original factory settings, I wouldn't suggest getting rid of it.
To be quite honest with you, only non-techies and grandmas who run into problems ever need it, so I think you will be ok.
Do you know how to remove partitions and add them, then format and reinstall? Let me know and I will check back in a little while.