Solution 2: Unmountable Boot Volume in Windows XP - Fix using other Computer
This option tends to be very successful.
Quite simply take the Hard Drive out of your computer, then go to a friends house, that is a friend who owns a Windows XP computer, and with permission open up his/hers computer, if its an IDE drive then disconnect their CD-Rom drive, and plug your hard drive in with theirs, of course make sure the cable is seated correctly and that the power connector is plugged in. If its a SATA drive then plug into one of his/her spare slots. Now power on their computer, booting of you friends primary drive.
Alternatively you can mount it in an external ESATA or USB drive mount, attach and start up the computer. This has fixed some very awkward "unmountable" problems.
Your friend computer will now boot up and run Chkdsk before it logs into Windows, let this run & complete.
Take your Hard Drive home and test. This method has a good success rate.
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