Desktop Operating Systems and Recovery

HP Compaq 6000 Pro MicroTower Win 7 64bit refurbished 

Had trouble with graphics about 8 months ago, support forum advised that I didn't need  a graphics card, that my computer had internal graphics and would work without it, and it DID! It was recommended that I purchase a new graphic card, PCI Amd radeon, and I did, but never got around to installing it.  PC still worked fine all this time.

I purchased a refurbished HP Monitor 32's 31.5 in Mfg date 2020.   Both PC & Monitor have worked fine for last 4 months.  Turned PC on 3 days ago, and Monitor said "no signal."  At first i assumed problem was with the monitor, so I switched VGA to an older 18" HP Monitor which DID receive a signal and was able to watch videos and carry on as usual.

I researched the newer monitor, and after some time, I thought that maybe my PC might have been too weak for big screen monitor & eventually stopped functioning (I remember a few times, recently, that the screen went black, when trying to enlarge maps on a certain site, and the error message was "graphics card stopped working" but then the screen came back on)

I wanted to use my big screen and finally decided to install the recommended AMD Radeon PCI card and insert the two new 4GB Memory cards I had at the same time.

Stupid me, I thought I would try to see if the failed NVIDIA Graphics card might still work and that perhaps it had just been jostled and unseated during a recent apt move.  It did not work and now there was "no signal" on both Monitors!

I removed the NVIDIA and installed the AMD Card and two 4GB Memory cards, filling up all the slots.  Turned on PC and got a loud beeping sound, & flashing red light coming from the starburst icon directly under the start button, and a fan came on really loud (I had never heard the fan before).  that continued for several seconds while I tried to catch my thoughts about what to do, so I tried to turn PC off manually at the stat button.  THAT did not work, so I could think of nothing else but to pull the power cord.

I removed the PCI card AND the new memory cards, plugged power cord back in, and connected the VGA  cord to both PC and older Monitor.  Pushed start button and the loud beeping, flashing red light and loud fan all started up again.  The Computer did not function in any other way than just those 3 things.

Is there any hope for me, my PC and all the stored information on it??

I tried to give you as much information as possible that I thought my be relevant to the experts here on this forum., to be able to form an opinion.

Thank you for any advise you may choose to share...