As stated above the partition is used as a "hidden" dynamic partition that can be used to restore your system to its factory defaults if you have a problem. If you already have backup and support media you should be able to remove this partition without worrying. To elaborate on the method above, I will provide a process that has been documented with varying success over the web.
If disk management is not your cup of tea, than I would suggest contacting the manufacturer regarding a possible approved method of removing the partition. If you want to roll up your sleeves then try the following.
step 1.) BACK UP. I recommend cloning your drive in the event you have a problem. If there is anything you can't afford to lose then by all means back it up! If worse comes to worse you will have to reformat.
Step 2) You can run diskpart as mentioned below
- Click Start-> Type diskpart in the search box (not needed if running from command line)
- type "list disk"
- type "select disk X" (X is the disk you believe contains the EISA)
- type "list partition"
- type "select partition X" (being the identified offender)
- type "delete partition"
- type "delete partition override"
Step 3) Try using a 3rd party partition tool like partition magic to extend your primary drive using the now unlocked partition. Want a free partition tool? try Gparted live cd or EASEUS Partition Master is also free, but I've never used it)