1) You can create a system image with a program like Macrium but given your current problems the image will be equally buggy, so it doesnt make any point.
2) You have 2 options. If the computer came with Windows 7 preinstalled, you can call acer support and request for recovery disks for your model- they'll likely ship it at a small cost. Then you can restore using those disks.
The other option is to get hold of a Windows 7 install dvd (borrow from friend or download a clean copy off the web), then do a clean install and activate by calling MS.