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- What data is lost when remove CMOS battery?

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10-04-2021 10:23 AM - edited 10-04-2021 10:24 AM
Motherboard: Memphis-S (Manufacturer name: Pegatron)
Motherboard Firmware: American Megatrends
What data is lost when I remove the CMOS battery?
I installed updated motherboard firmware some time ago. It was an update from what actually shipped with the computer. Will that I have to install that again?
What I have to access the motherboard firmware (pressing F10 while computer is booting) and change all that back to how it was before I removed the CMOS...?
10-04-2021 10:40 AM - edited 10-04-2021 10:41 AM
Hi:
Normally when you remove the CMOS battery, only any changes in the BIOS settings you made from the defaults will be lost.
When you replace the battery, the BIOS will be set to its defaults.
You will need to make any changes to the BIOS that were set to their defaults.
If you have added a legacy video card, you will have to remove it, or the PC will beep, and you will have no video until you remove the legacy video card, turn on the PC, disable secure boot in the BIOS and then replace the video card.
You will not have to reinstall any BIOS or firmware updates, and no changes should have occurred to the operating system.
10-04-2021 10:59 AM
OK, then you made no changes to the BIOS to add a legacy video card.
When you have a HP PC with a UEFI BIOS and you want to add an old video card (Nvidia GT 6xx or older, AMD Radeon HD 6xxx) or older, you need to disable secure boot before installing an older model video card.
You should be fine. The BIOS settings will be set to their defaults.