I have a Toshiba C55t-A5370 Laptop. I ran AVG PC Tune up on it and it killed it. I mean it did a total hard drive wipe out on it. Even the hidden partition was gone. It had Windows 8.1 on it and a friend put Windows 7 pro on it because he had the disk for it. It's alright but I'm not crazy about it. I downloaded the Windows 8.1 upgrade onto a flash drive but am not sure how to go about putting onto my laptop. Help please?
@Brea - I suppose you did not create recovery disk before messing with your laptop. Once your recovery partition is gone, your only option is to get in touch Toshiba' customer service, and order Recovery Media. How you will get it depends on where on the Earth you are (here is a link for Europe). You will most probably have to buy / borrow an external DVD drive as well.
The upgrade you already downloaded is no good without working WIndows 8 installation.