Switching from Win8 to Win7 will replace Win8 on your HDD so follow the instructions to backup your current system (1xDVD, 1x16GB USB stick).
All the information is available on the forum in a number of excellent posts - perform a search and read all you can find before you do anything! There are a few 'Gotcha's' you will need to watch for but, as I say, all the info you need is here.
Acer is proud to announce the promotion of Philetus to the ACE team. Philetus has been a member since March 2013 and has shown the skills and patience required to be a member of this exclusive, invite only team of experts. Congratulations Philetus!