My computer won’t start up

Every time I start my computer it freezes in middle of the POST test. I get the following error message.
Checking NVRAM..NO NVRAM

CMOS/GPNV- Checksum bad
press F1 to run setup
press F2 to load default values and continue

at that point hte computer freezes and I can’t do anything with it. even F1 or F2 don’t work. It’s a new machine. I tried switching the ram, but that didn’t help. I tried switching the battery- didn’t help either. I also removed all the expansion cards besides for the video card. Do you know what could be wrong? what does the error message mean? What is NVRAM?