Please provide Make/Model of your Windows7 computer, and whether a desktop or laptop.
Since it's a Windows7 computer; the hard drive is 3-6 years old and has likely failed or begun failing.
I suggest you run the free SEATOOLS diagnostic from seagate.com and check the quality of that hard drive. Make sure to run BOTH the short and long tests. If SEATOOLS returns any errors, your hard drive is failing or failed, and must be replaced. Purchase a new drive replacement, install Windows7 from discs that came with your original computer, and repeat the Win10 install. It should work. Many of us Windows10 insiders who have been testing the product since last year have run into this sort of thing before. One of the main reasons that Windows10 upgrades fail is due to faulty or old hardware.
Ok, I've installed the SeaTools for windows but there are two types of short and long tests. Both under Basic Tests there are "Fast" and "Long" options under "Fix all" as well as "short generic" and "long generic" tests. Which options should i run?
My computer model is an "ASUS Desktop PC CM5675 Series" the hard drive failed about 2 years back and i replaced it with a 2 TB hard drive. The manufacturer (according to my device manager) is "Standard disk drives" and it is an "ATA Device" although I'm not sure what that means. SeaGate says that the Model Number is "ST2000DM001-1CH164" if that helps at all. I scanned for driver updates but there were none.
Basic short and long tests should do the trick. ATA drives are more commonly known as Serial ATA or SATA drives in the common vernacular. Here's a wikipedia article link that more thoroughly explains the kind of hard drive your computer has: Serial ATA - Wikipedia, the free encyclopedia
Test your drive, and follow my instructions above to replace if necessary. If your drive passes SEATOOLS, you can also go to microsoft.com and download theFIX-IT APP that will correct any problems with your Windows Updates. If this fails, you'll need to consider resetting your PC to original from Factory Recovery Discs if you have them or can make them. Remember to backup any and all personal information such as documents, photos, videos, E-mails, etc. to external media before doing this. And it's vital that you choose the Format Media option on the Factory Reset to wipe out all traces of the previous Windows install should you have severe Windows registry corrupt or a hidden virus such as a Rootkit virus.
Re-read my last Post, 2nd paragraph:
[If your drive passes SEATOOLS, you can also go to microsoft.com and download the FIX-IT APP that will correct any problems with your Windows Updates. If this fails, you'll need to consider resetting your PC to original from Factory Recovery Discs if you have them or can make them.Remember to backup any and all personal information such as documents, photos, videos, E-mails, etc. to external media before doing this. And it's vital that you choose the Format Media option on the Factory Reset to wipe out all traces of the previous Windows install should you have severe Windows registry corrupt or a hidden virus such as a Rootkit virus.]
Since the drive passed the diagnostic, you simply need to reinstall your Windows from Factory discs that came with your ASUS computer. This is called a Factory Reset. Your ASUS should come with a utility to make the Factory Discs, usually under Backup, Maintenance, or Recovery Media. In fact, I am working on an ASUS V500C laptop right now for a Customer that I did just that. Most modern laptops, Windows8/8.1 do not come with these discs, you, the owner of the Computer has to make them or purchase them. The software is loaded onto a hidden partition on your hard drive, where it can be accessed from Windows. You can also download the free User Manual from the asus website to get more specific information. If your Computer no longer can make those discs, you can purchase them directly from ASUS for about $29-$99 US and get them in 2-3 weeks.
Remember that a factory reset will wipe your boot drive completely clean and devoid of all personal information; hence the backup warnings I've given you. Also, any and all programs that you've installed on that computer since you opened the box or acquired it used from somewhere will also be gone. This will include such programs as Microsoft Office, Adobe Photoshop, Elements, etc. Those programs will need to be reinstalled from disc media, or re-downloaded from the Internet sites where you originally purchased them using a License key. If you've lost those license keys, you may need to contact the manufacturer of each program and verify your identity in order to get them again. In many cases, your software itself will be out of date, and the software company may offer you a discount on their updated product, but you will have to essentially re-purchase the software, so do not be surprised. Software licenses allow you to use the program, but you don't really own them.
Do not install any new programs or webupdates such as Adobe Reader, Flash Player, Java, Anti-Virus, etc. until you can confirm that your Win7 update error codes have abated. Once this is done and you've fixed the problem, you can begin installing these updates, and other application programs. Then, if the Computer continues to work, you can copy back your personal information from your external media backup onto the C: boot drive, and put them back into the folders where they originally resided. e.g. Pictures in your Pictures folder go back to the My Pictures folder.