Windows will not boot

For Windows 8 read this:
How to Use Windows 8 New File History Backup aka Time Machine for... and this:
Back Up Your Computer with Windows 8 File History For Dummies


If you are using Windows 7 try this:
6 Safest Ways To Backup Restore Your Files in Windows 7 8

try going to the bios and change the boot sequence for hard drive to cd
put the copy of xp in the external hard drive and reboot the computer
when it powers up it should boot up off the external hard drive
if that works go to computer --device manager and find recovery section
you may also go restore to a previous date and try for a fix from there
go google and get to microsoft and find that file download for xp and install it
if all that works shut the computer down and reboot back to bios and change back to reboot from hard drive
remove the disc from the external hard drive

The best you can try is to remove the external HDD and see if computer boots..

If it does, you know where the problem is..

If it doenst, reboot computer, start tapping F8, if you get advance boot options, try to boot computer with Save Mode, Perform system restore from save mode.

If the above doesnt work, you need to perform repair installtion of Windows XP.

Hi, you need to ensure your hard drive is set up correctly! To install XP first press the F1 key during bootup, select the primary boot device (your external drive) in BIOS, save changes and reboot, allow files to be installed, but when finished, select delete operating system, partion hard drive and reformat, allow system to reboot, then commence new installation of XP. If your problem persists it is most likely a bad section on your hard drive, and will need replacing.
Hope this helps

Its probably trying to boot from your external drive.

Go into your bios and reset your boot setting to HDD0 as your first boot device, Disk drive 0 second and floppy third, unless you want to boot from an external drive. That being the case select an appropriate order.

If the bios shows your external HDD as HDD0, then you have to work out which is the drive carrying the operating system and set that to your first boot device.

To get into the bios, watch the boot screen for a key to hit to enter setup, normally its the "DEL" key.

go into your 'update settings'. there is a section of where it asks you about how you want your settings set and where to send updates to. You may find the problem here. Check all the 'advanced' settings as well. If your Western digital is plugged in via USB and not requiring updates, unplug it while starting your system, after complete start up, reinsert the USB plug. It may show new devise found, then from here, you may be asked to reinstall it to stop the rebooting.

If you're using windows XP then go to start > control panel > administrative tools > computer management > disk management. See if the disk is showing up there but hasn't been allocated a drive letter, if it hasn't then right click on that drive and press "assign drive letter". Be sure to do it to the right one, you could quite easily change another drive's letter by accident otherwise.

After doing some research it seems the beeping means that there is a disk failure.

Prop off the front of the unit, remove the drive and replace it. The unit will automatically rebuild the drive, which takes about 8 hours

set first device as your harddisk is bios.
When you power up the computer press F2 or "del" key to enter in bios.then go to boot option then set first boot as hdd.

Vista doesn't generally like to be installed on a hard drive that big. Well, Windows, in general doesn't.

And, from the sounds of it, you didn't install Windows on your new primary 1.5TB drive, you just copied it from the 500GB drive, which won't work.

Here's what you should to, to solve this:
1) Swap out your 1.5TB drive with the 500GB drive again.
2) Swap out your secondard 1.5TB drive, with the new one.
3) Create a partition of 120GB or less on that drive
4) Install Windows on the new partition.
5) Put the other 1.5TB drive back in, as secondary.

Once that's done, you can swap out the new 1.5TB drive with your Windows partition on it, in place of the 500GB drive.

When you boot, Windows may ask you to select which operating system you want, just select Windows Vista, and you should be good to go.

I had a similar issue a few years ago, when I tried to install Windows on a 1TB drive, and couldn't get it to work. Once I partitioned a smaller space, it worked like magic.