How do I fix or repair my HP mini 1000 Netbook with it being stuck in a boot loop? I am getting the "unmountable_boot_volume screen. My netbook does not have a CD ROM drive.

Unmountable Boot Volume means it did not detect your hard drive. Some laptops like HP have their own Hard Disk Diagnostic Utility. You can check that on BIOS. To boot to BIOS, restart your laptop and while its starting up, keep pressing F2 until you have BIOS Setup. You can see the Drive Diagnostic Tool at the top. Since you have the BIOS Setup Screen, try to set to default settings. Normally the default key by pressing F9. It will prompt you for YES or NO. Just press Enter for Yes the reboot it. If it does the same problem, make sure you don't have a USB flash drive plugged in. Try to boot your laptop to safe mode. Follow the steps below.

1. Reboot your laptop. When its firing up again, keep tapping the F8 key. You shold have the Advanced Boot Option screen.
2. Highlight the option that says "Safe Mode" and press enter. Wait for it to load the safe mode window.
3. Try to do System Restore. Click Start > Programs > Accessories > System Tools > System Restore. You can restore the computer back to date where it worked fine.

Check your bios to ensure its first boot option is set to the hard drive instead of CD drive or USB drive. If you have a thumb drive plugged in, unplug the USB and try again. On your boot screen there should be an option to hit a key to enter bios (Usually Esc, F2 or Del). Hit whichever key it requests and enter Bios. Once in Bios look for Boot Order and check to see where the Hard Drive is in the order. If it is not set to #1 then do as it says to set it to the first option. Once done hit F10 to save and Exit and return to boot.