In a PC with deccent configuration, a game may still run slowly. This can be due to many issues related to the hardware of your system. To solve the problem, measures can be taken like the installation of the latest drivers for the motherboard and the graphics card, or by changing the integrated GPU of the system. Programs like anti-virus scanners that may be running in the background must be stopped. It is possible that the system may be overheating or maybe the game's requirements are not suitable for the system's configurations. The latest version of DirectX being installed will also help. All these issues that can hamper the performance of the game must be checked.
I just bought a new PC and my games are running slowly on it.
You can try the following things:
a) First, install the latest drivers for your motherboard and graphics card
b) Disable any program settings running in the background, such as anti-virus scanners (you can do this using the control panel)
c) Check for overheating
d) Check out the minimum requirements for running the game. If the specs are to high for your PC then try to reduce the game settings:
Reduce Texture details
Set graphics : to Low or Medium.
e) Sometimes new PCs come with integrated GPU, this is not ideal for gaming.
f) If you are running Windows Vista with only 1GB of RAM, it will not be sufficient for gaming purposes. Consider adding more RAM.
g) Make sure you have the latest version of DirectX installed.