Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

Ok, new issue. Need to update the firmware on my bcr-2 charger. To update this, I need Etube project 3.4.5. To install that, I need NET 3.5 framework on my desktop.

First of all, what the fuck. Its 2021.

But more importantly, Ive done everything I could in terms of windows troubleshooting:

1. Turning NET 3.5 on in "windows features on/off" in control panel,
   throws all different errors and doesnt succeed in installing
   
2. Windows update troubleshooter, shows error but does nothing about it
   
3. Group policy settings edited as suggested in windows support docs
   
4. Deleting & renaming SoftwareDistribution and Catroot2 folders, forcing it to recreate them
   
5. Trying to force install from command line (leaves same errors in dism logs as the control panel route)
   
6. Latest security update....etcetc
   
   

Im at the end of my IT capabilities here. ....Anyone around east london / central / SE that has done this before and I could plug my charger in to update it?

Am I going to encounter more surprises that I'll need the older etube project for? Maybe its time I do a full wipe and reinstall of my desktop anyway...