Seeing that you've run chkdsk /r without resolution of the problem then I suggest you use the Dell diagnostics program to rule out a problem the hard disk itself.

Sounds like Bad Sector(s) on the Harddrive in the boot file area which are not repairable

If the hard drive is still detected by BIOS and you have access to a desktop computer running Windows 2000 or XP then I suggest you go out and purchase a 2.5" to 3.5" IDE adapter.
Remove the laptop hard drive and use the adapter to slave the laptop hard drive to the desktop. You should now be able to copy across any essential data from the laptop hard drive to the desktop operating system.

Well it won't startup so is there anyway at all to backup everything on the computer? I called Dell and their sending a technition to replace the Hard Drive but is there anyway to back up the files on it? And is there anyway someone can tell me what exactly could of caused this? Is it a fault or because of something I've done.

Thanks.

You never did report what model LT, OS version and format you are using?

All I can really say is its a Dell Inspiron 8600 with Win XP, Intel Centrino and no I cannot access the desktop the error comes after the Windows XP loading thing comes up.

What Bacillus is suggesting is for data recovery in a different computer- a PC- using an Adapter to allow connecting your laptop harddrive to a standard PC IDE Cable as a slave to the PC's  Harddrive as Master. Since the LT harddrive is then no longer being used as a boot drive, you should be able to access & move your personal files and data to CDRWs, CDRs, or even to a New Folder on the PC's Harddrive/Desktop . You must have a jumper to install on the LT Harddrive in the Slave position to do this method, or if the PC's Harddrive is configured for Cable Select, then you will need to jumper the LT Harddrive as Cable Select also and use the second plug on the IDE Cable to connect it. The only problem with these suggestions is finding a jumper for the LT Harddrive, as they seem to get lost, and a standard jumper is too large. If you can not find one, you can temporarily jumper your CDRW or other optical drive on your PC as a Slave, and put the unjumpered LT Harddrive in as Master in the Secondary IDE channel. Either of these cofigurations will work, but the latter is usually what I use.

Hi!       I have a very similar problem to the one that ITALY has. The same "Unmountable_Boot_Volume" message shows up, but the additional information says:

0x82F9A900,0xC000009C,0x00000000,0x00000000)...Do you think my harddisk is also damaged?

 I can still work with my computer (Inspiron 8600), but at every startup it shows this funny message and I have to choose "last known working configuration" and then it takes minutes to startup

I think it happened after I installed an older children's game that uses DirectX8.1

Try System Restore when up under Windows and pick a restore point before the game was installed. You will lose the game installation, but may save yourself a bunch of grief.

Thank you, guys

I tried the system restore option, but that failed several times

Then I ran the diagnostics CD and the program found the following errors:

Error code 0F00:1A44

Msg: Block 4493311uncorrectable data error or media is write protected

The same message showed up for three other blocks (4562519, 7563775, 7564031)

Does this tell any of you anything?

Yes. Since your harddrive is not write protected, you very likely have developed some bad sectors on it in a critical file area. If you can still boot up to the Windows Desktop either in normal or Safe mode, click open My Computer, click your harddrive Icon and select Properties. On that window, Click the Tools Button and then select Error Checking. It will prompt you that the Error Checking will take place when next you reboot. Restart the Computer and let that run. If it reports Bad Sectors, it may be able to patch them, but it is then time to look for a new drive