I'm not sure about what DRM you are talking about but if you use a good firewall and anti-virus/malware scanners (Comodo firewall and avast! anti-virus/malware are both free) then you won't have any trouble. I use those and have no problems. The scanner catches whatever tries and stops it. I've been virus/trojan free for years on XP, Vista and win 7.
Digital Rights Management (more properly and less ironically named Digital Restriction of Media) is a way for the big media companies to decide whether or not you get to use the data that you have. You are a thief until they decide otherwise.
Digital Rights Management manages digital rights like jail manages freedom.
DRM on Windows 7 does things like artificially crippling an otherwise normal, uncrippled cable television channel.
On the malware/spyware issue, what you are saying is that provided that you use additional software to protect your Windows system you could very well have trouble. And this makes Windows 7 no different than all of the other versions of Windows that came before.
I've been virus/trojan free for years on XP, Vista and win 7.
You know, I hear this a lot. I never hear someone say, "My machines are all eaten up with bots and malware!"
Yet somehow there are botnets that have 10,000,000+ compromised Windows systems in them.
The reality is that the new botnet malware is very discrete. You could easily be infected and not know it.