Windows 7: NTLDR + non system disk error

Intro
Hey guys, I have an HP Elitebook laptop. I got it new about 2 years ago and have had it attached to a docking station since I bought it. Connected to the docking station is an external hard drive where I store a complete backup of my laptop (I use the program "Norton Ghost"). I should probably also mention that the HP laptop used to have Windows Vista installed on it. I installed Windows 7 over it.



The Problem
Recently when booting my computer I have noticed that I sometimes get a NTLDR or non-system disk error. Two things confuse me about this:
1) They only started within the last 4 months. I haven't changed anything.
2) They are random and don't always occur.

My attempts
First off, here is my current boot order:

Notebook Hard Drive
Notebook Upgrade Bay
USB CD Rom
USB Floppy
External SATA
USB Hard Drive
Docking station upgrade bay
... some other stuff

Playing around with the boot order yields interesting results. If I change the order, the NTLDR error will disappear an the non-system disk error will appear and vice-versa. I would tell you the exact cause-and-effect relationship but I don't remember.

Help would be greatly appreciated.

Thanks!

Bump to the top.

To the best of my memory Windows 7 doesn't have NTLDR. I believe XP was the last operating system that use it.

NTLDR is winxp or win2000 stuff. One of the boot devices causes this. Put some other device on top for example "Notebook Upgrade Bay". If "Notebook Upgrade Bay" has some crappy winxp stuff you see that error. Test it and put the order back later.

Laptop is booting from "Notebook Hard Drive"???? Put is as the only possible boot device

Sure, will attempt this now.

EDIT:

Attempt 1
I moved the "Notebook Hard Drive" to the top of the list and disabled everything else. Unfortunately now it has the tendency to hang on the "HP Invent" startup screen... sometimes it goes through and sometimes it just seems to get stuck. It doesn't respond to any input in this stage.

I turned the "startup from upgrade bay" option on temporarily. It's still hanging on the startup screen. Sometimes I restart and it's fine, other times it gets hung up. I have yet to get any NTLDR/non system disk errors though, but I'd rather have those than the hang-ups. Any thoughts?

Also, I had disabled something called PAXE internal boot, could that have been causing the hang-up problem?

Most tech enthusiasts won't even run a factory preinstalled OS which is corrupted by layered bloatware and duplicate factory utilities which have better versions built into Windows 7. But you have on top of that an in-place Upgrade of Windows 7 which transferred all the crap and corruption from the bloatware AND the worst OS ever, Vista.

And the error you're getting is from an even older OS which has somehow leeched into your boot loader.

If there was ever a candidate for a Clean Reinstall - Factory OEM Windows 7 you are the one.

Thanks for the response. Yea, I kind of figured that was necessary. The previous person who did the Windows 7 install on my employer's computer apparently didn't wipe the old hard drive, which contained the older iteration of Windows. I mentioned a clean re-install to my employer but the problem is it'll take 40 or so hours according to her (re-installing old programs, restoring settings to what she wants, etc.).