PXE-E53: No boot filename received

Not the sort of message you want see see when you've just installed a new OS and rebooted, especially when it's followed by:

PXE-M0F: Exiting Intel Boot Agent.

The message certainly gave me a sinking feeling. Fortunately I had a Live USB handy, booted into CrunchBang!, and checked out Google. Bios set to do a Net boot? Bios not recognising the HD? Nothing in the BIOS settings seemed to apply. After half an hour of searching, I found another suggestion: the BIOS wasn't recognising the HD because it wasn't finding a partition flagged as bootable. I was doing a dual-boot install, and GParted in CrunchBang! was showing my new Wheezy partition as bootable. I tried making the Squeeze partition bootable and rebooted, taking the precaution of crossing both fingers.
The computer booted into Wheezy! Not quiet sure why, or how to get it to dual boot, but it was a start. I played around with Wheezy for a while to put off the problem of was I ever going to see my Squeeze installation again. Later on I had a look at a few threads on the Debian Forum and saw a possible solution. It seemed far to easy to possibly work, but it did:

update-grub