Donna de-partitioned her hard drive and now her computer can't read the drive. A partition tool can be a very dangerous thing and it's very easy to mangle the boot record. The best thing to do at this point is to re-install Windows. She doesn't need a partition at all, just make it one large drive.
One other thing to try is to buy a version of Windows 7 and install it using her install key. She may also be able to restore from the restore partition. She can press F8 (or F11, F10, or F1) at boot. This is one of the frustrations of not getting a separate disc when buying a computer. She can Contact Dell and ask them for install discs. For a nominal fee, they'll send a set to her.