Dopaminous

No problem having to reinstall the programs, I actually wanted to just wipe everything and only save what I use most, since my PC really needs some cleaning, but I don't have anything to backup my files.
But will Steam games work fine? I have some really heavy games to just reinstall. I know the games in my second HDD will work fine, but what about the ones in C:? If they don't work I can just go to "check local data" (something like that), and Steam will recognize them so they work without reinstalling, right?

I want to upgrade to Windows 10 through a clean install and I thought about getting a SSD and installing Win10 on it, making it the primary boot option.

I don't necessarily need to remove the OS from my current HDD, I just need to be able to access the files inside it and execute programs without needing to reinstall them.

Is it possible?

I know this is a probably a pretty basic question, but I don't have too much PC knowledge and I've never tried dual boot before to know.

@oursin_360 I did the tests with one at a time, it's the main HDD not being recognized by the BIOS.

Well, guess the HDD is pretty much dead and I'll need to buy another. Thanks everyone who took some time to help.

@oursin_360 Not sure, BIOS let me choose from 2 SATA devices (both my HDDs and optical drive are SATA). One of them is the one that was set as primary boot before, then I changed to CD now, but the first one set I believe was my primary HDD, since it started loading Windows before the blackscreen, but that would mean my secondary HDD is not being recognized, what makes no sense since this wouldn't stop Windows from booting.

BIOS pic:

I can't boot safe mode neither with or without cmd, it just restarts (because of an option "restart computer in case of initialization error" but if I check it off, it just goes bluescreen of death).

When I choose repair system on the Windows CD, the system won't appear on the list and if I choose "load drivers" I don't know what I'm supposed to select, if I try to select the E: drive (the one Windows is installed on - Which is weird cause it always showed Windows installed on C: and the other drive being E:, but here they are inverted-), it opens instead, so I don't know what file to choose from, maybe something inside the system32 folder? Sorry, I'm not good with this.

Here are some pics because I believe my explanation is confusing:

Anyone? :c

So, I removed the GPU but forgot to remove the HDDs, went straight to BIOS "BIOS configurations have been modified", then I chose "load recommended and reboot", after rebooting it showed that screen with "Start Windows normally" or "Repair", no matter what I choose, it loads a little bit and then blackscreen, but I can access the BIOS now. And by removing the HDDs, it gives the no boot device message: "Reboot and select proper boot device or insert boot media in selected boot device and press a key". What should I do? Run bootrec.exe by booting with my flashdrive?

@dayve86 The keyboard lights come on normally, about the splash screen, nothing happens, only thing I noticed is that it took kinda long before showing the GPU screen, but I don't know if it's normal since I always turn my PC on and go do something else before actually using it, since it's kinda old and loaded and takes some time to load everything. And I just entered BIOS once with this PC, but I didn't have any problems back then.

Another thing I noticed about my PC is the temperature. When I'm using it normally, it stays around 60ºC (140ºF), and when I'm playing something, it goes up to 80ºC (176ºF), don't know if that's normal temperature or too hot.

Tried everything here, the RAM switchs, booting with only mouse + display + keyboard, plugged the keyboard in every usb port possible and yet no success, can't get into BIOS and also no POST, just the two screens already mentioned. Only thing I didn't try yet was @zelyre's idea about taking the GPU off (also, the NumLock's light is working normally), I'll try it later and if it doesn't work, guess I'll have to take the PC to be fixed. Thank you all for your help.

When I turn on my PC, it shows the Motherboard's Splash Screen followed by the GPU information screen and then it goes blackscreen forever.

I've tried removing the CMOS battery and putting it back on, but no success.

I also tried to access the BIOS but nothing happens, it just goes to the GPU screen even though I'm pressing DEL.

I've had this problem before, I thought it was my HDD diying, but my friend said he just cleaned the parts with some specific product and it worked.

Setup:

Processor: Intel Core I7-3770

Motherboard: Gigabyte GA-H61M-DS2H Dual UEFI BIOS

RAM: 2x Kingston DDR3 1333 4GB

HDD: 2x 1TB Storage

GPU: PNY GeForce GTX 780 3GB GDDR5

Font: Corsair CX500

OS: Windows 7 Professional x64