The boot record on a Dell E310 was modified over time as a result of various system updates. I was unable to access the restore partition, when the OS needed to be restored, using Ctrl-F11 at the BIOS boot screen. To restore the boot record so that I could use Ctrl-F11, I created a bootable DOS CD using the fdfullcd.iso from the FreeDOS site (http://www.freedos.org/). Then, I created another CD with the dsrfix.exe (http://www.goodells.net/dellrestore/files/dsrfix.zip) utility on it. I unzipped the dsrfix.zip file and burn the contents of the zip file onto a CD.
From here, I booted the FreeDOS CD. Then, I removed the FreeDOS CD and put in the dsrfix CD. I ran mscdex.exe at this point. However, I do not believe that was necessary. Then, I switched to the E: drive and ran dsrfix. I had an alert on pbr descriptor 3. Next, I ran dsrfix /F. This repaired the record so that Ctrl-F11 worked. Thanks to Dan Goodell (http://www.goodells.net/dellrestore/). According to Dan’s site, his utility has been tested on the following Dell systems: Dimension 1100, 2400, 3000, 3100, 4550, 4600, 4700, 5000, 5100, 5150, 8200, 8300, 8400, 9100, 9150, B110, E310, E510, E520, E521, XPS 400, XPS 410, XPS 720, XPS Gen 4. Inspiron 500m, 510m, 600m, 630m, 640m, 700m, 1150, 1200, 1300, 1501(AMD), 2200, 5100, 5150, 6000, 6400, 8600, 9300, 9400, B120, B130, E1405, E1505, E1705, M710, M1210, XPS, XPS Gen 2, XPS M1710. Vostro 200.