I will not use any Windows version later than XP because, as I see it, Microsoft's "digital rights management" additions to the system are both highly undesirable from the user's point of view and ridiculously expensive.
The standard reference on this is "A Cost Analysis of Windows Vista Content Protection":
http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.htmlThe author is a well-known security expert.
Historically, general-purpose operating systems have always provided
discretionary access control. You get to set permissions on your files; the user controls any sharing.
People like military and intelligence organisations, though, have had
mandatory access control; the system manages access. If a document is classified "secret" and "project wombat", then only people with those clearances can see it. Moreover, they can only use cleared systems and cleared software. You cannot print Wombat report version 1.0 unless the printer has clearance. You cannot load it into an email application unless that app is cleared. The cleared email app will not send it unless the recipient is cleared. Depending on the route, it may also enforce encryption approved for "secret".
Mandatory access control systems have always been very expensive. Partly this is just that anything done on a gov't contract tends to be high-priced. partly that it is a relatively small market, but also partly because it is a difficult task.
Vista introduced what amounts to mandatory access control, grafted in on top of existing Windows stuff, to protect "premium content". You cannot send high-resolution material to an uncleared display, for example; Windows will degrade the output to protect the precious content from unauthorised copying.
Screw that! My
personal computer should do what I tell it to, without consulting policies built into Windows that give media companies a veto.
Apart from that, adding mandatory access control wastes large amounts of both CPU and memory.