My configuration: Dual boot: W8.1 on a SSD, W7 on a HD, all user files from both W7 and W8.1 are on the W7 HD.
The only reason for keeping W7 in the air was a NLE (video editing) which did not function well in a W8 environment.
What should be the best / least risky way of upgrading my W8.1
Henk