Its possible that you have been ransomware'd. Hackers out there are highly skilled at tracking down peoples crypto wallets and ransomwaring them. The thing is if you were ransomware'd you'd get a ransom note to pay the hacker to decrypt it.
What makes you think it is encrypted?
It looks more than likely that your windows install is borked to me.
Do you still have access to the file/ folder system that the app is installed in? If so I would:
1. immediately copy the data inside the application folder (specifically the wallet file or if you can't be specific the whole folder) it to a USB stick (ideally 2 or 3 USB sticks as borked windows can fail catastrophically any time)
2. locate another machine and rebuilt it with a fresh OS. Windows 10 minimum.
3. download and install the app back onto your clean OS.
4. copy and overwrite the files from the USB into the other system that is clean built
Most likely this will work. I don't think you have been ransomware'd.
You may have been straight robbed however. This is also unlikely though depending on how you answer these questions:
Have you been downloading dodgy software and installing it?
Have you been watching movies downloaded from file sharing sites?
Is your OS older than Windows 10?
If you answered yes to any of the above you are at risk of being hacked. Its easy money for the hackers if you know how. Lets say im a hacker. I put put a RAT (remote access tool) into a video that I upload to the pirate bay. That video gets 1 million downloads. I write a script to search all my RATS for bitcoin wallets. I steal them all. I laugh and go any buy the misses a £1000 bottle of champagne.
I work in IT security. I am on the right side of the fence bro (white hat). Most likely you are OK. Its probably just Windows has **** the bed.
Leave the PC intact. Copy the files out. Get another clean built PC. Try again over there.
Also, if you are dealing in crypto, get a cold storage wallet. They are (almost) unhackable. I use a ledger X nano.