Well try running it in "Safe Mode" and see if it will run faster/fine. If it does, there is something(s) that are on it that are running in the background that are using up your resources. In that case, you would need to locate what it is/what they are and remove them. Worst case you would need to do a clean install of the OS and any other software (backing things up beforehand of course).
How to enter "Safe Mode" when booting the computer.
In Windows 8 and 10...
As your computer restarts, press F8 (possibly a few times) to enter "Safe Mode"
a. Press the "F4" key to Enable "Safe Mode".
(The computer will then start in "Safe Mode" with a minimal set of drivers and services.)
b. Press the "F5" key to Enable "Safe Mode" with...