Hi Viktor,
At this time, we do not have separate Windows-specific installation or upgrade instructions for DSpace. However, DSpace 7.x can be installed on Windows. You can follow the same instructions.
If you encounter an example command which is specific to Linux, just use a corresponding Windows command.
For example, in Linux, you may run this to migrate your database: "./dspace database migrate ignored", while in Windows the corresponding command is simply ".\dspace database migrate ignored".
So, you should be able to follow the same instructions with minor changes for Windows:
That said, if someone out in the community has written up their own Windows-specific documentation, then hopefully they will share it here!
Tim