Open Disk Management. Do you see a Recovery Partition?
I would first download Advanced Token Manager to a USB key and backup your Activation files. Unzip the program to a folder on your USB flash drive. Backup the activation files. They should be backed up to the folder you unzipped Advanced Token Manager to. Make sure the files are there before doing the factory reset.
See this Dell thread. Supposedly you can start the factory reset by searching for Winnt32.exe. Make sure you write down the key that was shown when your ran Advanced Token Manager.