You have Windows XP Home with service pack 3 running on a Dell tower since 2007. Operating system will not boot up due to "Unmountable_boot_volume" error. When attempting to boot up in safe mode using original Windows XP service pack 1 CD a same error appears including a following message ***STOP: 0x000000ED (0x8B047C30, 0xC0000006, 0x00000000, 0x00000000).
Where can you get help in recovering from this error? You cannot boot system in safe mode even with original Microsoft CD. If you haven't already, can you check and even reseat the IDE cable that is connecting your hard drive to your motherboard.
Are you able to boot into Recovery Console off that Windows XP CD? You can try booting into "Enable VGA mode" via that F8 advanced boot options menu. If successfully boots into a Windows desktop, then you can remove video drivers in "Add/Remove" programs.
Reboot your computer and if it boots normally you can then reinstall video drivers. You can try to boot into Recovery Console off your Windows XP CD. From there I can walk you through some steps to resolve your issue.
If you press F12 as soon you power on that computer a boot menu should open, where you can choose your CD-ROM or DVD-ROM drive to boot from. There could be a hardware problem with that hard drive. If it was just corrupt Windows files Recovery Console would normally work.
You can boot back into that F12 menu and look for a "Diagnostics" option. There should be some tests you can run to test your hard drive. You have a failing hard drive with most likely a hardware problem.
I recommend taking it to a data recovery place or computer repair shop to see if they can get any data off of it. I think your computer is probably fine, you just have a failing hard drive. I would recommend taking it to a place that offers free shipping or no charge unless they can get data recovered.
I would take it to a place that specializes in data recovery if your serious about getting any data recovered. You can contact Dell at 1-800-WWW-DELL or visit this Dell hard drive data recovery web page.