Based on a translation of a German interview first done by Rock Paper Shotgun, it seems that DRM has struck again with stopping legitimate copies of games being played, but this time around it's specific to Windows 10. A big amount of these cases revolve around the disc-based systems of old, which include games like The Sims, Microsoft Flight Simulator 2004, and Grand Theft Auto 3. Specific cases have already popped up in the Microsoft support forum as well, as files like SECDRV.SYS is causing problems for SafeDisc as well, it's not in the Windows 10 builds. Microsoft's Boris Schneider-Johne made a couple of statements about the problems at this year's Gamescom, as shown below.
Everything that ran in Windows 7 should also run in Windows 10. There are just two silly exceptions: antivirus software and stuff that's deeply embedded into the system need updating - but the developers are on it already - and then there are old games on CD-ROm that have DRM. This DRM stuff is also deeply embedded in your system, and that's where Windows 10 says "sorry, we cannot allow that, because that would be a possible loophole for computer viruses.". That's why there are a couple of games from 2003-2008 with Securrom that simply don't run without a no-CD patch or some such. There are a couple of patches from developers already, and there is stuff like GOG where you'll find version of those games that work.RPS did contact SafeDisc and they commented indicated that the DRM hasn't been supported for years now, and the driver hadn't been updated for a long time, but they were surprised that it wasn't moved over in the migration to Windows 10.
I'm in the process of contacting Microsoft to get their comment on the story and any information about if there are any planned fixes for the problems in question. The decision to maybe hold back on some of these elements however may have been purposeful due to possible security holes (as mentioned by Schneider-Johne), but it is unclear if that was fully intentional or not.