Sorry I'm so late today in replying - as is fairly common in the repair business, several emergency repairs had to get done (so that my clients could go back to enjoying their weekends).
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Windows 8 Installation DVD
You mention that you now have a Windows 8 installation DVD. If it is the same type as your computer's Windows 8 (for example, Windows 8 Pro 64-bit), you should see a prompt when you start your computer with it:
Press any key to start computer from DVD. When you see that prompt, press the
Enter key on your keyboard to continue.
Note: there is a guide that has screen-shots for each step of this process, you can refer to it to get a more visual look at it ---
How to Reinstall Windows 8 with Large Images
Next you should see a screen that asks what language and keyboard type you want - if you are in the US, and prefer English, you can accept the defaults and click
Next. On the next screen, you'll see a prompt to enter your Windows 8 product key.
Enter the product key from your original Toshiba Windows 8 (it should be on a sticker on the bottom of the laptop). Then click
Next.
Since you want to completely start over, you can next click
Install Now, and then click to
Accept the license terms, and click
Next.
Select
Custom as the type of installation you want. Setup will next ask you "Where do you want to install Windows?" ... select
Drive Options (advanced). You will want to select and then delete at least two of the partitions, so that Windows can replace them with new ones. Do NOT delete the Toshiba Recovery partition - make sure to leave it alone (it is probably about 12gb to 20gb in size). The two partitions you want to delete are a tiny little partition of about 100mb to 400mb that contains Windows 8 recovery files, and the original main Windows 8 partition, which should say "System", and which is usually the largest partition on the drive (generally about 320gb to 700gb).
From here the rest is fairly straightforward - pretty much follow the prompts. Let Windows install to the empty "unallocated space", and allow it to create its little system utility partition. The system will reboot during the installation of Windows 8, but DON'T press a key for the restart prompt "Press any key to boot from DVD" - because you do not want to boot from the DVD, you want to continue installing Windows 8.
When all done with reinstalling Windows 8, you can then restore your documents and pictures and other personal files from your backups.
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Windows 8 "repair disc" DVD (or USB)
If it turns out that you don't have a Windows 8 installation DVD, but in fact have a Windows 8 "repair disc" DVD, which you made from the instructions in one of my earlier posts, you should have seen a screen from which you could choose to try a System Reset, System Refresh, or Troubleshooting. Should a System Reset not work, you could then go on to trying some utilities from the Command Prompt, which you can access from the Advanced Options menu. These steps get a bit more complicated, so I'm going to point you over to a site with step-by-step instructions that can walk you through each process. Pay special attention to the points they raise about the "UEFI only" setting in some computers Bios settings, that is very important if your computer's hard drive is partitioned as a GPT drive (don't worry, it's all explained very clearly in the article ... and it's explained a couple of times!). Here's the link ---
Repair your computer in Windows 8 | www.winhelp.us
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If you take your time & follow the steps one at a time, I think you should have a pretty good chance of getting your Toshiba back to normal.
And if too many things went missing with a partitioning accident, don't worry -- you always have the option to order new Recovery DVDs from Toshiba. They shouldn't cost much, and they definitely should work.
Once again, I'll check back to see how you're doing. (Though on Sunday mornings, I am fond of some coffee, chocolates and the crossword puzzle ... so it might be a little bit later than average: and, luckily, I'm more of a baseball fan than a football fan .... )
. . . Gary