Generally a microprocessor Run slow If the speed setting are not correct or due to some dust near that processor.
There are some troubleshooting for the slow issue and hanging issue for your computer or laptop:
Use blower and clean the system.
Use a thin layer of heat sink compound on the top of the processor.
Check whether the microprocessor is compatible with the motherboard by repairing to the manual. the issue also come when you are using an unsupported processor on a motherboard.
Check the CPU fan weather is properly rotating at its recommended speed.
Check the CPU fan if its dusty or dirty.
Check the jumper setting on the motherboard and the BIOS setting of the microprocessor and change to default settings.
Check with the microprocessors supports the application that you are running.
Some related questions to this post:
Troubleshooting for processing issue of a computer?
My system Hanks down again and again what to do?
How to solve processing and hanging issue of a laptop or computer?