There are a few ways to check if your computer is 64-bit. 

One way is to go into your computer’s BIOS and check the information there. Another way is to use a program like CPU-Z to check the information about your CPU. 

If your computer is 64-bit, you will be able to use more than 4GB of RAM. You will also be able to use 64-bit software. 

If your computer is not a 64-bit computer, you can still use 32-bit software. However, you will only be able to use 3GB of RAM. 

If you want to use more than 3GB …