I have a COMPAQ 615 laptop, currently running Win 7. Wanting to upgrade to Win 8 PRO, I successfully downloaded Win 8 which took about 5 hours. The installation seemed to go fine, but then I got the message "installation was unsuccessful, restoring your previous version". (Which it did). No explanation about the failed install. How do I get past this? Must I start the download all over again, or can I just redo the install process? I have already paid for the download and don't feel like paying again! Did you run the Windows 8 Upgrade Assistant first? Run that first; it will give a list of software that needs to be uninstalled before upgrading, software you will have to reinstall, and any other things that are known to CAUSE problems. Look at the manufacturer's website (in this CASE HP) for your model and see if there are upgrade instructions from the manufacturer as well.

You should be able to reuse the download and redo the install process, but like I said first CHECK the manufacturer site and the Upgrade Assistant.Also if the DLoad took 5 hours you may want to grab a fresh one from someone with a high speed connection...common errors in the install with funky DLoads would be a CRC error for example.
The key you purchased will work on any new DLoad.Yes, I used the Upgrade Assistant. I have now been able to install. I think the problem is that during the download, the Assistant gave a message "Feel free to use your PC". So I assumed I could also do this during the installation - oops, wrong. So I closed every app in sight before doing the installation, and it worked.

Though I'm not overly excited by the new OS!
Thanks again.Good to hear you got it running...