That is the BIOS setup screen. What happens if you press the Esc key to exit? Does the system boot, or does it come back to the BIOS setup screen?

Where did you see Windows asking you for your license key?

If I press ESC out of there, the computer tries to boot up again and goes back to that initial screen. It asks for the installation disk. Pressing F8 does nothing but take me back to that initial screen.

Sorry for the delayed response. Your computer is going to the BIOS setup screen because it cannot find a boot device. That means the boot drive in your computer has a corrupted file system or the drive is going wonky. It is not even getting to the point where it can start booting Windows. I think your first task should be backing up your essential files (i.e. files that you created, but have not backed up. Documents, spreadsheets, photos, etc.). That can be done by booting the computer using a USB stick or DVD with an OS on it. Knoppix is a Linux distro that is specifically made for that purpose.

Boot from Knoppix and then copy the files to an external hard drive, or even Google Drive or Microsoft SkyDrive. Once you have backed up your user files, you can see if you can recover your computer. There are other "Live" variants of Linux, such as the Ubuntu @Slash McCoy mentioned. Of course, this all assumes that you are familiar with Linux. If you are not, suggestions to use it without further assistance are rather pointless. It is a good thing to learn, though.

Windows 7 install DVDs can be purchased online. The price depends on the seller and Windows 7 version. Please keep in mind that Windows 7 is no longer supported by Microsoft.

Before you proceed with anything, I recommend going to a computer forum, such as https://forums.anandtech.com/, and asking for support there. It is a better source of digital geekery and bit twiddling magic than a wetshaving forum.

I called up the BIOS screen by pressing DEL at the right moment, apparently. I sent away for a 1Tb flash drive, that, according to Amazon, won't arrive until at least April 17th. Microsoft is no longer selling Windows 7 and any package I purchase is likely to be an illegal copy, so I don't think that's gonna be possible at this point. I have absolutely no familiarity with Linux or Ubuntu.

Why do you think it would be an illegal copy? The places still selling Windows 7 are usually electronics and software surplus resellers. They buy or take donations of old stuff, including unopened software packages, and sell it. If you do go this route, the version of Window 7 you buy should match what is on the PC.

Like I said, you would be better off checking with the Anandtech forum. This place seems to have turned into a ghost town.

Last year I purchased what I thought was a legal copy of Adobe Master Collection CS6. Apparently it wasn't, so now I get pop-up windows on my screen telling me it's an illegal copy and that the program will shut down in 60 seconds, and I can't close the window without first having to arrange my Task Manager so I can deactivate that window before it pops up via the Processes tab.

Have you ever considered open source alternatives to the Adobe apps? For example, GIMP in place of Photoshop? There is a learning curve, but it comes at our favorite price - Free! It might be worth a trip to your local library to see if they have any instructional books for GIMP and any other free apps you find.

Ok, for Windows 7, not all copies sold are fake. Computer surplus store take old computers and resell them, and often sell old (as in ancient) versions of Windows and apps. These come from businesses clearing out old inventory, companies or stores that have closed, etc. Think of them as the digital equivalent of Army surplus stores. You might even be able to find one near you. If not, then there are some online. Checking the BBB for complaints can help sort the chaff from the wheat.

I've tried GIMP. It's simply unusable for me.

I'll see if I can locate a seller who is reputable. Maybe it'll even have the Adobe Master Collection CS6...Problem is, my state is on lockdown, so no telling when or if the places local to me will still exist by the time it's all over.