If anyone reinstalled and have battle net app stucked at 45% here is working solution:

[Thorack-veknilash (Thorack)]

I have found how to reinstall battle net without it being stuck at 45%.
Change the network temporarily to mobile hotspot (don’t download the game it would cost a lot for some).
After battle net installs turn off mobile hotspot and do WMI restart in Windows:

net stop winmgmt

winmgmt /resetrepository

net start winmgmt

It should not work and download game files trough your ethernet or whatever is not mobile network.

[Darandin-burning-legion]

That does not fix anything. Still stuck at 45%

[Thorack-veknilash (Thorack)]

Have you tried to unplug your ethernet if you have one? I did, just don’t forget to switch back to it for game files download.