I appreciate your offer and maybe I'll take you up on it, but I have received similar images from others (again, which is why my scope is actually working now).
My experience with installing software (much like others) is to install the OS first, and then install the software (Agilent in this case). Per your instructions, I'm installing the software first, and then installing XP from the CD, correct?
Keep in mind, my "original" HDD isn't original. This unit had channels 2 and 3 as a 50ohm failure. Shortly after buying it (fully knowing the two channels were bad) the SSD hard drive got corrupt. I'm uncertain if the hard drive was an image of the original, but the owner sent his saved image to me, however, it didn't boot the Agilent software (Windows booted fine, but it never initialized into the scope software).
This lead me down the path of trying to find an image online. Someone sent a (approx.) 22GB full image, another sent a smaller image, etc... All of which I was extremely grateful for. Eventually I found an image that worked, but all I had was a 120GB spare drive and said screw it, let me use this.
Now I have a few images from various people (with at least one known good one), a 120GB drive that works fine in my scope, but only occupies a fraction of the drive, etc... As mentioned, I'd like to keep back up SSD's should this one become corrupt. In doing so, I'd like to install a raw Agilent version rather than stealing an image from someone else (even though they work fine).
On a side note, per your question on whether I'm comfortable disassembling this scope. I actually fixed channels 2 and 3. I traced the circuits by hand, discovered a previous owner changed a few components, the Agilent hybrid chips were bad, etc... I bought used hybrid chips from China (possibly fake?), researched which part types were replaced (all thanks to the help of people on here) because one was a three legged component that I didn't have a clue what it was, etc... Also had to replace a broken ZIF connector, replaced the power supply fan, etc...
I replaced the components, questionable components, hybrid chips, calibrated, self test, etc... and the unit works like a charm now. Needless to say, I'm quite comfortable with getting inside this unit.
As for why I'm not leaving well enough alone. Again, it's mainly due to wanting backup SSD's and finding that I need to reduce the existing 120GB size rather than waste money on 320GB drives, and, while I'm at it, maybe I can upgrade to XP (or just have a raw image to install).