I'm traveling to the US from Malaysia and I will be bringing my computer desktop and monitor. Will I face any issues with US customs?
Generally speaking, you will not have any problems.
However please note that software piracy is a serious offense in the US and if you are suspected of carrying pirated software, your hard drive may be confiscated.
Please make sure you place your desktop and monitor in your checked-in luggage; because if you bring it with you in your carry-on - according to new rules, you'll be asked to turn it on at the security checkpoint. If you cannot turn it on, it will be confiscated.