Hello Mindsclay,
Thank you for posting your question in Microsoft Community. We are glad to help you.
To help you suggest steps to resolve the issue, I would appreciate if you could answer the following questions:
- Does this issue persist with all the programs?
- Which program are you referring to?
- Were any significant changes made to your computer prior to this issue?
- Did you save the priority after changing it?
You may have a look at the picture below for changing the priority of a program in Task Manager.
Please reply back to this response we will be glad to help you further.
Thank You.