Computer will only boot if a certain HDD is in it

[xNikolai]

So I have 3 HDDs one of which I am getting rid of because its dying. Another one is brand new and blank and another has my OS (windows 7 on it).

The one I am getting rid of has XP on it which I dont really use anymore. But for some reason my computer will not boot unless this disk is plugged in and powered on. If its plugged in it will still boot into windows 7 which is on another disk just fine but if the XP disk isnt in there it wont accept the windows 7 disk as a valid boot disk.
This is the first time Ive really done anything with have multiple disks and multiple operating systems so I have no idea whats going on. I need to figure this out before the XP disk dies completely as I cant really afford taking a day off work to figure it out after the fact.

My Mobo is an Asus Sabertooth X58 with an i7 950 processor.

Any help would be greatly appreciated.

 

[Indigo]

The drive holding Windows XP has the MBR (Master Boot Record) on it which points to the Windows 7 install, which is why Windows 7 won't boot when the XP drive isn't present. You would have to rebuild the MBR on the second drive either by running a repair option (boot to the 7 CD, then choose "repair my installation") or you can use utilities to do it, but the first one should work fine.

 

[bloobnoob]

Good answer og. Just follow what og said and if you have more problems just give post back in this thread.

 

[xNikolai]

Thanks Og. Unfortunately my computer does not have a DVD/CD drive at the moment. I can barrow or buy one later this week but would like to get this done today.

Any suggestions on a utility I can use to do it?

 

[JCB1]

Thanks Og. Unfortunately my computer does not have a DVD/CD drive at the moment. I can barrow or buy one later this week but would like to get this done today.

Any suggestions on a utility I can use to do it?

On a PC with a CD you can copy the windows 7 CD on to a USB stick which will make it bootable. Take a look at this guide Maximum PC | How To: Install Windows 7 from a USB Key!

 

[xNikolai]

Thanks for the help guys. Issue resolved.