Athlon II? What is this? A server for ants? ;-)
That seems quite underpowered to be honest. Jellyfin per default does quite a lot of things per default during startup or as a background job. Sometimes you need to dig deep into the config settings and also disable certain timed jobs.
What OS are you running on?
How much storage do you need and how much are you willing to spend?
Playing lots of RPGs and Jrpgs has trained my Patience. I never buy a game at full price, regardless of how much I want it. I simply wait for a sale until it’s below 35 euro.
Which email provider is the account with?
Once you understand how the Linux bootloader works, restoring it is easy if windows breaks it. The other way around is more tricky if windows refuses to cooperate.
That being said, using a rescue usb like systemrescuecd will allow you to boot a Linux OS even if the bootloader isn’t working properly.