Re: Continually having to repair the MBR ("no boot device available") Dell Dimension
I too have have the "no boot device availble" message on my 8400.
My workaround was to open up my Dell, Unplug my DVD ROM and RW drives, Re-plug the top of my ribbon cable into the second drive(my DVD RW), and move the plug coming from my hard drive to the mother board to the spot labled with the number 2.
When I closed my case back up and restarted it, it let me boot from the DVD RW drive. I then choose my hard drive and attempted to erase everything from it. When I checked my SATA hard drive, I notice that there was still something hiding on it. I clicked on the UP arrow and discovered a RED FOLDER labled with WEIRD NUMBERS that did not go away, and it wouldn't let me delete it either (that selection in my menue was GREYED OUT).
I attempted to UNMOUNT IT several times so I could finsh the erasure of my SATA hard drive. On the last attempt, it let me. But not before putting something that I suspect I probably don't want (the reason for the format in the first place) someware else (my screen turned dark grey and I got some message saying that my hard drive was busy).
After that, I was able to unmount and completely format my hard drive. Suspecting that something was wrong with my hard drive anyway, I installed UBUNTU linux on it so I could still work with it untill I could REALLY fix it.
I opened up my machine again, pluged everything back to where I got it from and it started the same "JACKED UP" way. But at least with UBUNTU on it, I can download VirtualBox, install "Windows" (which might not "officially" run ("cough" "hint") there either because its on the same"JACKED UP" hard drive))
inside of it, and install my apps from there.
Long story short. I think most if not all of us that are suffering from this "boot device not availble" error may have been infected by a "BOOT KIT VIRUS or WORM"!
If you notice, it won't let you do anything that could result in you getting it OUT of your system. It appears to "run and hide" or "clone itself" to somewhere else if you find it. It changes your motherboard settings so that you can't do a "clean install" or run a Virus removing program.
What's worse, it appears to infect the motherboard too, so that if you do get it off your hard drive or buy and install a new hard drive, it will just put itself back onto the victim hard drive later on from somewhere else on your motherboard!
You get it? It seems to go from one place to another so you can NEVER get rid of it (kinda like holding a hot potato in one hand and repeatedly switching hands)! This "thing" is having a "symbiotic" connection with your system (Motherboard and Harddrive)!
The only solution I see is to find a way to "wipe" this mess out of your mother board, perhaps with an app that can run "live" from your CD or DVD drive (see how I did it), then run a "live OS CD/DVD" AND erase your hard drive so you can get a fresh start.
OR you can just buy a brand new motherboard AND hard drive, put them both in at the same time and "call it a day".