Hello Hervé,

There is a known problem that for some users, the Help / Software Update command does not work, going from version 2.1 to 2.1.2. In that case, please follow the instructions at www.notation.com/Redownload.htm for re-downloading an entire new copy of Notation Musician 2.1.2 (or Composer 2.1.2). You should be able install it "on top" of your copy of Notation Musician 2.1, without having to restart Windows. However, if Musician 2.1.2 doesn't run after installing it, please do try restarting Windows.

Cheers
-- Mark