Installing windows 8 upgrade on mac

Have Imac with Snow Leopard OSX 10.6.8 installed with Windows 7 on Bootcamp part ion. Tried in vain to install Windows 8 Upgrade disc via Bootcamp but not getting anywhere. Firstly, the installation disc is not recognised and keeps being pushed out. Have downloaded the Windows Support Drivers on to flash disc, but on clicking on Instal Windows 7 section of Bootcamp and installing Windows 8 disc is as far as I get. Can someone please explain procedure for installing Windows 8 Upgrade over the top of Windows 7 on my iMac. Thanks, Nick

Since Windows 8 will install over the top of Windows 7 as an upgrade, there is no need to use the Boot Camp assistant. You should be able to boot to Windows 7, insert the Windows 8 DVD and click on the install.exe file. It sounds like your optical drive may be having problems though. Also, is this a MS boxed copy of Windows 8 or is it a disk burned from an iso purchased from MS?

Hi chscag, Thanks for your fast response. I'm using an MS boxed copy of Windows 8 and did first try to instal when in the Windows 7 partition before trying Bootcamp, however it would not accept the dvd. Think you may be right in that the optical drive may be shot - have tried a movie dvd and it is also being rejected. Now wondering if I took out Apple Care ???? Thanks for your input. Nick

Before contacting Apple, buy a can of compressed air which you can usually find at stores which sell electronic items and computers. Blow several short blasts of air into the optical drive to see if perhaps that will allow the disk to be recognized. It's possible the laser light may be dirty inside the drive.

Thanks for suggestion - bought can of compressed air and tried, but no go. Apple tech. coming next week to solve problem - thank goodness we took out Apple Care! This iMac is actually my daughter's on a horse farm and office is full of dust all the time, so thought that your suggestion was the answer! Thanks again. Nick