It's a good point about using the Windows 7 system repair disk for Windows 8. I do not know if that has been tried before or even if it is possible. Both use the BCD store for booting. But because this happened after Mcafee was uninstalled, I think it has affected more than just the boot files. I googled and found other people had the same problem of a blank screen after an uninstall.
Try the following first.
Remove the power cord and battery. Press the power button for 30 seconds. Attach the power cord but leave the battery out. Power up the computer.
Are there any files that need to be recoverd from the laptop?
Levono has a button that will start the factory reset process. It's called the NOVO button and looks like a little arrow. I am not sure where it is on your computer but if you do a factory reset, all files that were put on the computer after purchase will be deleted so do not do this until you have recovered all of your files.