Hello and welcome to PC Help Forum.
As you did not give us make and model of the CPU you bought answering this question can be a bit difficult.
However looking at your Compaq PC it is a PIII.
I have looked into intel CPUs and the max I can find for this machine is Intel 733 mhz.However this is debatable as computers are usaly updated over time.
Product Description
Product Description
Compaq Genuine Celeron 600/128/66 CPU Presario 5BW 7EL 5000 Pc Series
Product Details
- Product Dimensions: 6 x 4 x 3 inches ; 2 pounds
- Shipping Weight: 2 pounds
- ASIN: B0002HT1N8
Amazon.com: Compaq Genuine Celeron 600/128/66 CPU Presario 5BW 7EL 5000 Pc Series - New - 196362-001: Everything Else
So although you have bought correct socket the issue could be compatability.
Your mainboard is not compatable with the CPU you bought?
More RAM/Memory would of given your PC speed.
And install XP this would update your computer.