I think maybe I was not clear when said:
if we don't install additional drivers and let the system use those it has into it.
I was thinking in those lovely drivers for nVidia or ATI graphic cards with an stupid size of several GB.
But on the contrary I have installed on the first 8.1u1 x64 VHD before recapturing it as wimboot all this:
Word and Excell from Office 2003 + compativility packages for read/write/save Office 2007 and newer files.
335 MB of Portables on Documents: (this is optional as they can be outside the VHD to save size but I wanted to test a full portable with all my favorite programs included.)
Diskmod: to can deal with multi partitioned USB sticks (remember Windows is capable to do it since 10 1709).
SVBus driver: to latter can RamBoot the final VHD
7 Zip 19.0.0
SoftPerfect RamDisk (v3.4.8 Free): to latter create every boot a 512 MB RamDisk (it can be any size AFAIR upto 4 GB in free version) NTFS compressed A: drive to load there FireFox profile (with all my markers, uBlock Origin, preferences, etc copied from my everyday OS) just after booting, this is to keep my VHD on 1 GB and do not delate loading on Ram at the moment of booting a biger size, since I can create additional volatile RamDisk for FireFox every boot, and do not keep on VHD all internet cached info, allways same clean profile is loaded. Of course same could be done with some changes for IE-11 and Chrome (The haviest an more prone to keep a tremendous amount of cached info from internet)
FireFox 65.0: I didn't have available at the moment the offline instaler for v65.02 (the very last) but procedure is the same, and it was good enought to run a test.
And still have about 400 MB free space on the VHD after first boot, I will verify this info to give more acurate numbers and add a picture latter.
This is all required to put FireFox profile on RamDisk:
Install SoftPerfect RamDisk (v3.4.8 Free) create a disk to be loaded every boot, select the size you want, select disk letter, select removable (recommended) select NTFS, select avanded and on the new window only select compressed disk and acept, and acept again on first main window.
Download offline instaler on your language for last version of FireFox, Without conected to internet install FireFox on running VHD, run it once, it will not connect to any place, that's OK, then close it and go to \Users\YourName\AppData\Roaming\Mozilla\Firefox\Profiles located on your daily use OSs and copy the file inside profiles called someting like xxxxxxx.default (it is recommended to previously have ran CCleaner on that OS berore doing this to clean as much as possible the profile before copy it). Then just paste this xxxxxxx.default file inside the profiles folder on VHD and delete the one created when first ran the program, open and edit profiles.ini as following or using the letter for your personal created RamDisk, and the actual name of your *.default file
Now following is my Profile_RamDisk.cmd, edit it as required to your needs and put it next to profile.ini file, make a direct access on desktop, that needs to be run before running FireFox, or to make it automatic open start menu and copy the link on the place to be loaded every boot it is "inicio" on my Spanish menu I know translation is "start" but I can't be sure as I'm not running any OS English version, hope you understand what I mean, it seems a little ugly each time the command runs, to avoid this I made a little .exe with Bat_To_Exe_Converter just selecting invisible application (this is an old version wonko kindly recommended me, but makes smaller .exe) and use this .exe same way as the command file then.
XCopy C:\Users\YOUR-NAME\AppData\Roaming\Mozilla\Firefox\Profiles A:\Profiles /s /i
You need to change YOUR-NAME and RamDisk letter as required.
Of course some will say it is easier to just make a biger size VHD about 2 GB since the beggining, but I want to keep the VHD on a maximum of 1 GB to load it faster on RAM, also I have in mind this VHD can be RamBooted easily on 4 GB Ram equipments (actual minimum standard on new equipmentes since at least 1 or 2 years), and still have enought Ram available to let all programs work fine.