After some web search, I finally discovered this page, which exactly deals with that problem. To disable mouse acceleration, some changes have to be made in the registry. You can download a registry key and apply it in order to do so.
There also is a restoration key, which will set back everything to normal. Well, in fact it leaves out some settings, which probably are dependant from your current config. If you want to be sure about it, I advice to compare the installation- and removal-keys and note down the missing options in their current state. In case you didn't do this and need them later on, I can as well provide my values, which I edited into the restoration key before setting up the new ones.
Anyway, these settings perfectly disable mouse acceleration for me and I can finally play these old games like they're supposed to be played. And even better: I discovered that mouse acceleration is in no way needed for the daily work in Windows - at least for me. In fact, I can hardly notice the difference, so I stay with mouse acceleration disabled. I thought I'd make a forum post about it, as some of you may find it useful as well.
