I would try going to the safe mode first http://windows.microsoft.com/en-US/windows7/Advanced-startup-options-including-safe-mode I am not sure which options will be avilable to you but you can try the repair option first and then safe mode with command prompt http://ss64.com/nt/diskpart.html SELECT DISK=0 CREATE PARTITION PRIMARY ASSIGN LETTER=C SELECT PARTITION=1 FORMAT FS=NTFS LABEL="New Volume" QUICK EXIT

Hi, I have an Acer W500 Tablet running Windows 7. I was goofing around with it to see if I could dual boot Android (x86) software. I installed Android O/S (from http://www.android-x86.org/), which required installation of GRUB as a bootloader so I could go back/forth betweeen Windows and Android after the install. It worked fine a few times (i.e. switching between O/Ss) but then just stopped. My Acer will power up, and I can reach the BIOS, but when I select the HD with Windows 7, it gives me "Error 15" with no further explanation. I have the acer install disks, so I went into BIOs, rebooted from the DVDs, and re-installed Windows 7. But, even after the install was complete, when the computer rebooted from the HD it still gives me "Error 15" -- I Think Error 15 is a "file not found" error, it's as if BIOS doesn't is looking for windows in the wrong location (?). -- Maybe the GRUB bootloader I installed is mis-directing or overiding my BIOS somehow? -- My recovery disks do not over a "repair" option, only a re-installation of WIndows. Maybe I can buy/download a Windows 7 recovery console that allows me to check/repair the existing WIndows ? -- I've heard that "flashing" the BIOS might help repair any errors in the BIOS. I downloaded the latest BIOS from ACER to a flash drive, and tried to boot from the flash drive. But this doesn't work. Maybe I'm doing this incorrectly? Any/all suggestions would be appreciated. I'm not very comp savvy but am willing to work with specific guidance.

Windows 7 has by default a small partition (100 mb) where the boot files are loaded. If i had to guess what the problem would be is that Android has changed the security here or partition file system type. I don't think that the problem can be resolved by flashing the bios. You can try repartitioning the hard drive and reloading the windows then. (diskpart)

Thanks for the reply Brano. Any idea how I could access the drive on this tablet in order to re-partition it? It is a tablet with an SSD drive which is probably not removable from the device (like it would be with a laptop). Would it be possible to access the SSD from another computer using a USB to USB connection? Thanks.

I would try going to the safe mode first http://windows.microsoft.com/en-US/windows7/Advanced-startup-options-including-safe-mode I am not sure which options will be avilable to you but you can try the repair option first and then safe mode with command prompt http://ss64.com/nt/diskpart.html SELECT DISK=0 CREATE PARTITION PRIMARY ASSIGN LETTER=C SELECT PARTITION=1 FORMAT FS=NTFS LABEL="New Volume" QUICK EXIT