Just dealing with a false alarm past 2 days myself, so please take that into consideration that you might just be experiencing typical windows system problems rather than a rootkit.
In any case, PnP and DCOM failing alone is NOT a symptom of a rootkit or virus UNLESS it's coupled with hidden system services obvious signs of slow down, website redirection and other strange errors. If it's only happening with the same game but not anywhere else, it's mostly like just generic issues. E.g (in order of likelyhood):
- a video driver issue (mostly likely)
- a recent update to the game or the Steam engine itself may be incompatible with your hardware/driver/other software on the system
- hardware issue
- failing RAM
- failing video card
- failing power supply
- other software driver issue (CD/DVD burning software, antivirus software, DRM'ed software)
- a new Windows Update is incompatible with your game
What it's likely NOT:
- MBR rootkit: you already reinstall and reformat windows, that would have replaced your MBR with a fresh one.
- a rootkit virus: unless you experience the same error while NOT playing this pariticular game, I highly doubt it's a rootkit on your system.
- SSD: if it gives you the same error when playing from HDD, then it's not the SSD. Though you should think about what other software you installed since you got the SSD since you said the problem arose the same time. This includes Windows Updates you installed and drivers you updated.
- BIOS: unless you've changed BIOS settings right before the problem started appearing, it's probably not the cause.
If you scanned with multiple virus scanners, and the one you used are already known to have very good rootkit detection, it's probably NOT a rootkit. But try GMER and 2-3 bootable CD scanners (Microsoft offline scan tool, Kaspersky, DR Web and Avast come to mind) too if you want to be safe.
I'd suggest check Steam's forum whether any other users have seen the same errors running Steam engine or this particular game recently.
Also, I'm assuming that you acuqired this game and other games on your system via legit channels. I don't think you can pirate Steam games, but if you have other pirated games on your system, it may have cracked drivers that are not malicious but can interfere with this game. Video game protection usually hook into the system very deeply, so even legit games you've installed recently can cause issues. Other software protection scheme can also cause these kind of problems (e.g. audio production software like CuBase, DRM software, etc.).
Here's my recent exprience:
https://superuser.com/questions/471007/need-help-identiying-a-nasty-rootkit-in-windows
