Can't Reinstall Windows 7 (URGENT)

[DaWalrus]

Hey everyone. I have a computer issue that needs to be solved urgently. Before I begin, these are my specs:

Gateway GT5678 Computer
AMD XFX R7 260X Radeon Graphics Card, (Note: I used to have an ATI Radeon HD 2400XT Graphics Card, but I upgraded it).
300 V Power Supply Cord
Intel Core 2 Q6600 Quad-Core Processor
Windows 7 Home Premium Service Pack 1
(This info is basically in case there's any hardware incompatibilities I didn't know about).

Okay, now for the actual problem. For a long time now I had been having random BSODs and restarts. They weren't particularly frequent, but were nonetheless an annoyance. They never resulted in any damage aside from irritation, and only happened every couple of days, until recently. About six days ago it rapidly would start bluescreening and restarting. First it would only stay on for about 30 minutes at the max. Then it would only stay on for 10. Then 5. Then like 30 seconds. Now it won't even come on. I can't even reach the login screen before it messes up again. I start up the computer, it does it's thing, and then it says "Windows is loading files" with a gray loading bar on the bottom. Then it will either BSOD, restart, or go onto Startup Repair, which does absolutely nothing. Mostly it goes to Startup Repair. BSODs and restarts are pretty rare in specifically this case. I finally ran Startup Repair and it said that my "Boot Configuration was Corrupt".
I finally decided that reinstalling Windows 7 would probably fix it. Now, this is VERY IMPORTANT. I HAVE TO KEEP ALL OF MY DATA FILES. I HAVE TOO MUCH ON HERE TO LOSE. I went into Startup Repair, and chose the startup recovery option, the one that allow you to do this. It was Gateway Startup Recovery. There were three options: One that would completely get rid of everything, one that would reinstall the OS and keep all of my data files, (AKA the one I need to use), and exit. Except, the one I need to use is grayed-out and not selectable. Then, I tried putting in a USB with the actual Windows 7 OS on it. I put it into my USB port, and booted it up from the boot menu. It started up great, and I selected to update since it would keep all of my files. Then it says that Windows must be running in order to run the installation, and told me to take out the USB, login to my computer, and run it from my desktop, except, I can't get to my desktop. Nothing I try seems to work. I need to do one of two things:

1. Make the grayed-out option usable.
2. Find a way to get the Windows 7 reinstallation USB to run somehow, with or without Windows running.

What I want to know is how I could do either of these? I have to quickly too.

I also want to say that I cannot back up my info. Once again, I can't even reach my login screen, and I also don't have anything nearly big enough to hold all of my stuff.
I also seem to have trouble reaching the Advanced boot menu with F8. And alternative to reaching Safe mode would be appreciated.

I'd really appreciate any help you could give me. I've tried everything, and nothing's working. I need this fixed quickly, as I have a lot of stuff to do on this computer. Thanks!

EDIT: I forgot to mention that I've had this problem ever since I've had this computer, even with the old graphics card. That's probably important.

 

[DaWalrus]

Hey, everyone. What if I tried running all these commands in Startup Repair as opposed to running them from my installation/recovery USB? Maybe it's not directly affecting my PC or something because I'm doing it from the command prompt on the USB, not the command prompt on my computer. I can reach startup repair and any options in there too, keep in mind.

 

[Reyaz123]

Yes, highly suggest you do that

 

[DaWalrus]

Okay, I tried Reyaz123's commands and Martell1977's commands on startup repair. Reyaz's worked, but didn't do anything. Martell's didn't work because it wasn't on the USB. I guess the guide was specific to a USB, it had to be done on it's command prompt. So none of that did any good. Anyone have any other ideas?

 

[DaWalrus]

After some research, I found out that my graphics card requires a 450 W power supply, and my PSU supplies up to 400 W. So basically it barely works.
So I've decided that I'm going to go along with getting a new PSU. I have a family member who's really good at hardware, (not software, that's why I consulted you guys), and she'll find me the right one for me. I don't know what that'll do to actually letting me on my computer, but I need it anyways.
If it doesn't make a difference, I'm contemplating just letting it go and wiping my PC. It would be a big shame, but what else am I supposed to do? I'm not saying that that's what I'm going to do, so if you have any other ideas, please tell me. Like I said, wiping my PC was the last resort. So, keep bringing in possible solutions.
I also want to say thanks to everyone who's helped me so far. I didn't have the means to do anything other than this really, and you kind individuals spent your own time trying to help me solve my difficult tech problem for free. Thanks guys.

 

[Paul NZ]

Which is what I said

 

[DaWalrus]

Which is what I said

I never wrote off your response, I was just making sure that was the issue. After all, how bad would it be to end up upgrading a PSU, which is definitely going to be a difficult process, and find out that it was unnecessary? Good thing we caught that. I don't know how I missed that when I was looking into a new graphics card...
Speaking of a new PSU, will I have to get anything else to go with it to function properly? Like a better power cord or something?

 

[Paul NZ]

Just as long as its enough for the videocard you have and has the right connections (if the videocard you installed has power connectors) it should be fine

 

[DaWalrus]

Just as long as its enough for the videocard you have and has the right connections (if the videocard you installed has power connectors) it should be fine

Okay, I think I'm alright then. As long as it has the appropriate wattage, a six-pin power connector, and all the other required cables, (which I'd imagine most have all the other miscellaneous cables). Thanks for clearing that up for me.

 

[DaWalrus]

Okay, I'm looking into a new PSU. It seems my family member can't help with it, so I'm going to consult you guys. Now, my current PSU is a "Delta Electronics, Inc. 400 W DPS-400RB A". I don't know if that's the info you guys need, so tell me if you need more. Anyways, I need the best PSU possible that has at least one six pin connector cable, all the required cables like my current one has, a minimum of 500 W of power, and one that would fit in my PC. My maximum budget is $50. I will say that if one is notably better than the other, but it was like $60, I would spend the little extra.

 

[DaWalrus]

Okay, sorry for the long hiatus. I finally got it working. I ended up just letting it go and reinstalling Windows 7. Unbeknownst to me, if you do a factory reset but don't delete the partitions, the computer will take all your old stuff and save it in a folder called windows.old. So I was able to keep all my pictures, documents, etc. I was even able to save all my games and such. So it worked.
Now, as of today, my computer started freezing again. No BSODs or anything, just hard freezes. I am beginning to think that my PC is just dead and that I need a new one. The only issue is that I'm on a budget and that this computer wouldn't fetch nearly the amount of money to buy a new one. So basically I can't do that.
Everyone said that they think my PSU is faulty. Do you think this could be causing the freezes?