[Android Q&A, Help & Troubleshooting] gchatten:
For WINDOWS users (no root needed):

This also applies to DATA.VDI and any other VDI's installed in Bluestacks 2.

Bluestacks uses the UUID of the VDI which appears to be obtained from a Bluestacks server over the 'net each time it is started. I've found no way around this. Bluestacks wants to make absolutely sure you are using THEIR VDI's and thus if THEIR UUID's don't match your .;VDI files BlueStacks will throw an error on start.

There are no registry fixes or files that can be edited to replace the UUID in BlueStacks since it's checked "live" over the Internet.

To change the SDCARD size first copy SDCard.vdi from where you installed Bluestacks from the ANDROID directory and save it somewhere in case something goes wrong.

1. Delete SDCard.vdi from the ANDROID directory of BlueStacks

2. Make sure Bluestacks is closed. On Windows use Task Manager and kill all Bluestacks processes - include those that begin with "HD-". In a couple cases I had to restart Windows as well.

3. Download (free) CloneVDI from: http://downloads.informer.com/clonevdi/2.5/

4.. Run CloneVDI

5. Select the original SDCARD.vdi from wherever you copied it to as the source

6. For the destination select the ANDROID directory with a filename of SDCard.vdi

7. Under "Options" check "Keep old UUID"

8. Then check and enter your values for "Increase virtual drive size to" and check "Increase partition size"

9. Click "Proceed"

This nifty utility will not only create the new VDI with the same UUID but will copy all the data from the original for you!

The only issue left is the new VDI has a blank partition now so you can't use the full space yet in BlueStacks, so:

10. Using Ubuntu (or anything that will run GPARTED) - I used Oracle VB and selected the new VDI as a disk, SUDO GPARTED. Select your new SDCARD.vdi file. In GPARTED expand the current partition size to the maximum. Easy as moving the slider all the way to the right. Apply the changes, close down Ubuntu.

-- if you don't know Linux/Ubuntu then download Virtual Box and install. Then grab an ISO of Ubuntu and install that in your VM. If GPARTED is not found then download it by going to Terminal then type: SUDO apt install gparted

11. Fire up BlueStacks and check settings on storage and you should see your larger SD card and all the former data is still there..

WARNING: If you reinstall Bluestacks it will write over your new SDCard.vdi so make sure you save a current copy before an uninstall or reinstall of Bluestacks!

[Optional - requires ROOT]

I use Titanium Backup and many other apps on my phone so after starting up Bluestacks I installed ES File Explorer and simply copied my phone's SD Card contents to Bluestacks. Installed Titanium Backup and then restored what I wanted. Obviously do not install ANYTHING related to your phone's systems - APPS only. You need to "hand pick" even with a filter for user-only APPS but you will find some system APPS there too - uncheck them.

This is the cleanest and fastest way I've found to clone-a-phone and increase the SDCard size on Bluestacks 2.

Note there are many other methods I saw to increase VDI size but they will not work - not even registry changes. They appear to be for Bluestacks v1.x

There are also, with the BlueStacks program file directory, XML entries for UUID's. You can change them but every time you run BlueStacks it will over-write the file using one from their server.

There are also registry entries where you can change the VDI names and paths - it doesn't work.