won't get past first post

I would suggest if you have any warranty to take that route with Acer. You would likely loose all data on the laptop.

Another thing would be to try booting from a w7 install disk. I suspect you didn't get one since OEMs are so cheap thinking these days. All I know for sure is you have w7 HP 64 bit.

You can try a Repair Install which will keep your files. you would need to download the correct Windows version .iso file that your laptop sticker is for and make a bootable USB flash drive or a DVD. Instructions for all are here. I hope you have access to another computer, it can even be a XP machine.
Repair Install

You may be able to use the DVD to enter the Repair options too.
Startup Repair

Have you tried tapping F5, F8, F10, or F11 right after powering it up with the power adapter plugged in?

I'm out of ides. Just changing the BIOS to switchable graphics mode won't cause a no boot problem and no BIOS.
There has to be some hardware issue since you can't boot from anything else.

I'll ask for help.

Morzie, taking the small watch battery out for only 30 seconds will probably not reset the bios to default. You need to have it out for 30 minutes to 1 hour. Also the standard full size laptop battery OUT & the optional AC power supply disconnected during this time also. Also as soon as you power ON try holding down the ESC key to see if it will cause some sort of error that will result in getting into the bios setup.

Most of the time failure to boot into BIOS is a user failure. Vigorously tap the F2 key beginning the second you turn the power on. It should work unless the mobo was damaged when pulling the CMOS battery.

Were you extra cautious when you opened the case to get into the CMOS battery? You know that you must ground yourself by touching the case metal before getting near the mobo, right?

Sometimes battery needs to be taken out for awhile, drain the power fully by also holding the power button down. Of course everything should be unplugged, and no carpet around.

As a test carefully pull out the RAM sticks to see if the mobo beeps so you know it is responsive. Then reseat the RAM making sure there is no debris in the slots.

I would also try booting Acer eRecovery to see if the setting can be overridden by Recovery, realizing that if not you may need to somehow enter the BIOS again to change it back or even as a last resort reflash the BIOS.

Next try booting Hiren’s BootCD 15.1 which will boot itself without user assistance allowing you to copy out your data from the bootable XP explorer, run a HD diagnostics test for your HD brand, run a Memtest on the RAM, then if necessary wipe the HD.

This will force the installer to boot itself to Clean Reinstall - Factory OEM Windows 7.