Choosing which version to go with depends on what you intend to use this computer for. So it would help if you provide us with a little information regarding this.
It would also depend on what you intend to do in regards to upgrading the computer. If you use the 32-bit version you will be limited to 3GB of RAM, where as you can install as much RAM the motherboard will support with the 64-bit version.
In order to help you, please post the make and model of this computer.
Please download and install Speccy
to provide us with information about your computer. When FileHippo opens, click on Download latest version
in the upper right pane.
When Speccy opens you will see a screen similar to the one below.
Click on File which is outlined in red in the screen above, and then click on Publish Snapshot.
The following screen will appear, click on Yes.
The following screen will appear, click on Copy to Clipboard.
In your next post right click inside the Reply to Topic box, then click on Paste. This will load a link to the Speccy log.