unmountable boot volume

I was able to get to "Repair Your Computer" from F8 -- from there it went into Startup Repair -- I never had the opportunity to do a chkdsk, nor did I see a command prompt -- am trying again..

Am running the chkdsk C: /v/x/r  and will advise when I know more....

If you changed your hard drive controller to use AHCI in the BIOS, go in and change it back to SATA/IDE.

The cause of the problem is corrupt ntfs.sys driver. Normally chkdsk x:/r on system volume fixes this problem. So you are on the right track.

result of the CHKDSK /v/x/r test is as follows:
8 bad file resords processed
10 unindexed files processed
adding 127 bad clusters to the Bad Cluster File
CHKDSK discovered free space marked as allocated in the master file table (MFT) bitmap
508 KB in bad sectors
fialed to transfer logged messages to the event log with status 50

I am able to get into Windows Safe Mode now --
No restore points available
trying to elliminate startups to find out where the problem may be ..
when attampting to alter the startup menu, I get this error:
error 0x80070571: disk structure is corrupted and unreadable

Okay,

It sounds as your hard drive is starting to die.  Usually when I see more than 4KB in bad sectors, it's time to replace the drive.  With you having 508KB in bad sectors, there is the possibility that some data was lost in those sectors.  You can read more about what a bad sector is from here.  http://en.wikipedia.org/wiki/Bad_sector

I would also check to make sure you are not receiving these errors due to bad memory.  Download and run memtest 86+ http://www.memtest.org/#downiso You will need to burn it to a CD.

Best suggestion now is to back up your data onto an external drive in Safe Mode, then replace the hard drive.  If your computer is still covered under warranty, I would suggest calling your manufacturer up.  Chances are that the hard drive will continue to get worse the longer you use that hard drive.

If you need suggestions on a hard drive, I would suggest Western Digital.  
http://www.newegg.com/Product/Product.aspx?Item=N82E16822236345
You may also need to buy Windows, or if you have a key on the side of your computer (which you should), you can call up Gateway and ask them for recovery disks (for a small price, I'm sure).

Let me know if I can be of any more help.

as i said, i supposed already a bad disk -  so run the diag to know it's staus

for details, see my post above

Created the UBCD and am runnning Memtest86+    Been running for about 2 hours now and zero errors so far. Where do I find the LONG test on the UBCD? And does it make sense to run another CHKDSK /r?

I'm not too familiar with UBCD, though I do agree with nobus that it is a very nice program and tool to have!  I have used it several times for boot issues.  You can run another chkdsk /r, and it might repair the remaining issues, but if you have ANY more bad sectors show up beside the 508kb that you already found, the drive DEFINITELY needs replaced.

Hotse - iasked to run the DISK diag
running memtest is a RAM diag - it does not stop, you have to stop it yourself
the LONG test is part of the DISK diag, found in the HDD section
you could have found it if you looked on the UBCD site - lots of screenshots

good news -- got back into the system and it seems to be working and stable (seems is the operative word ...). I ran a last CHKDSK /r and no additional bad sectors showed up. I am warned, though, and will procure a new hard drive and safe guard my data.
Both pc-solutions50501 and nobus were helpful in getting to a solution, so I will split the credit between both of you. Hope you agree.
Thank you very much for your assistance.

Hotse Langeraar
www.hotse.com

Thank you very much for your help ...

Hotse, tx for feedback
if i may say so, i still recommend to run a disk diag, in order to show the staus of the drive
remember that chkdsk is not a disk diag, it checks the file system