Dead monitors and clearing CMOS?

So, I’m running into a series of headaches with my PC. First off, getting Microsoft installed was an absolute struggle. It was a mess—first, it claimed a file was missing, then I finally managed to get halfway through installing my programs, restarted when prompted... and then the machine just wouldn't boot. The hardware seems to be running, but nothing happens on screen, and the CLR/CMOS light on the motherboard is staying lit. I've dealt with this before on my ASRock board, and I found a temporary fix by pulling the CMOS battery from the motherboard to reset it—basically forcing the computer back to its last known state. But now? Windows is throwing errors about missing files, which is preventing me from even installing my graphics driver. To make matters worse, after a quick power cycle, I've hit a new wall: no video output at all. The tower sounds like it's running perfectly fine, and while I am using an old Samsung CRT—which honestly is a top-tier classic—I don't think the monitor is the culprit. I tested it with an LCD monitor my roommate uses, and that also shows "no signal."
If anyone has any smart ideas, I’d really appreciate the help.
😵🙂

First off, can you drop your full specs here? I need to know exactly what hardware we're working with and which specific version of Windows you've got running. Also, grab a Hiren's BootCD USB and run some tests—hit the RAM with memtest and check the drive using HD Tune.

How old is this build actually? What kind of specs are we looking at here? Has the machine ever even run reliably? If it did, what have you swapped out since then? And honestly, are you even sure that Windows DVD isn't bunk...

Pulling the battery just to make the problem vanish isn't a real fix. If I had to guess, you're going to have a hell of a time dealing with whatever issue this is if your motherboard is acting up intermittently like that...