Why jump from version 8 to 10? 3 possible reasons:
1. Latest version is 8.1, which is actually supposed to mean 8+1, that is version 9 for you
2. Skipping the good version number 9 and hopefully break the good-bad-good-bad cycle.
3. Imply Windows 7 is old. Look, you are 3 numbers behind if you are still using Windows 7.