Login into your node using SSH session is ONLY from another PC / device and is done using a terminal.
From windows 10, yeas you need to use Powershell.
You can reset your user data (only if you do not have any funds in that wallet/LN channels) following the instructions from Umbrel Troubleshooting Guide and start over.
No blockchain data is lost, only that you will be prompted to create a new user and save a new node seed 24 words.