According to your description, I suggest you refer to the following information:
1. The CPU of notebook products is highly integrated and customized, and cannot be directly upgraded. Improve the performance of notebook computers. You can consider upgrading from memory capacity, which is safer and more compatible.
Because it is an upgradeable component reserved by us, the associated interface also conforms to the unified standard.
2.2. The HP 540 notebook has two memory slots, one of which can support up to 2G667-MHz and DDR 2 memory;
Tips:
If a 32-bit operating system is equipped with 4G memory, it is normal that it will not make full use of all the memory due to the limitation of the system's own memory mapping access. If you want to fully recognize 4GB of memory, it is recommended that you install and use a 64-bit operating system.
3. If you confirm that the original spare parts of notebook can't meet the existing work requirements and want to upgrade the spare parts-in order to ensure the compatible use of hardware, it is recommended that you try to contact HP Gold Service Center for consultation and add original spare parts.
If you need to inquire about the contact information of HP Gold Service Center, you can use the following official links to inquire:
/zh/support-drivers/e support/as CPPS . html
4. If you want to upgrade the spare parts yourself, it is recommended that you take the notebook to test the spare parts on the spot and use it normally before buying, so as to avoid the notebook from working normally because of incompatible hardware.
5. In addition, since DDR2 memory is listed earlier, the price may be higher due to shortage.
I hope the above reply can help you.
If the above information can't solve your problem, you can log on to www.hp.com.cn/chat,, the online chat room of HP Network, and ask an online engineer to help you solve the problem further.
More product information is available in www.hp.com.cn/800..