I am currently Dual Booting Windows Vista and Ubuntu 12.04 on an Acer machine. I would like to install Windows 7 in place of Windows Vista, but would like to keep the files and programs I currently have installed on the Vista partition of my hardrive.
You have 2 ways to install a(n) OS. 1 is to do a clean install which it formats the drive where it erases all the data on the drive, which is the recommended way. 2 is to do an upgrade which leaves all your files and data as is which is what you're looking for. The only problem with and upgrade of an OS, is if your system is buggy or quirky it will reflect that with the upgrade. Sometimes the upgrade will be just plane troublesome, not for all installations but it does happen. Also with the upgrade, run windows upgrade adviser. This will tell you if you have any software, hardware issues which will be addressed before the install of the OS.