Hi. I saved up and bought a pretty good spec computer, almost 2 years ago. It came with windows 8 already installed in it. I decided to try to install linux to see how fast it would go on it as I thought reinstalling windows 8 would be easy, But when I installed linux ubuntu it completely wiped the hard drive partitions and I could not reinstall windows 8. I did not have a clue how to get windows 8 back so I went to ebay and bought ''Windows 8 repair and reinstallation media'' for 10quid. It worked a treat although when installing it was asking me for my product key. I could not find the product key in any of the boxes that I got my new computer in, and it was on no stickers on the computer. So after the install I found a program that could pull the OEM Product key from the BIOS or where ever it was. And it worked a treat. After this I went to microsoft website and ask them in live chat to confirm if this was my product key and if my windows activation was genuine. They agreed that it was the right product key my computer came with and everything was genuine. Lately Ive been a bit paranoid though as I do a lot of online banking and share dealing on my computer - wondering if whoever this random person was who sold me the repair media may have edited some of the windows files on the disc and when it was installing windows could have left it with rootkits or viruses or anything nasty. Or is that impossible? Anyone have any advice?