I run W7 and would like to make sure that my settings are optimal.  Currently, I've done nothing but disable my wireless adapter.
My performance may have been a little better prior to X3 and I'd like to check up on things.
 
Thank you!
James

You may not get as many replies or leads as you would have in the past because Windows 7 is pretty good out of the box.  I rarely tweak anything anymore, and I used to be a faithful follower of Black Viper and other similar optimizations.  They were necessary to squeeze performance from Windows XP, but not now.
 
About disabling the wireless adapter, wireless networking is a known problem with some systems, which you can confirm with the DPC Latency Checker (except for those who are running Windows 8, which isn't yet supported). 
 
The only tweak I do now is to alter the custom power scheme so everything is Always On.
 
One more thing, a blast from the past: there has been discussion about changing the Priority to Background Services, but this is not recommended by Cakewalk's Noel Borthwick.
 

I agree with post #2. Win 7 is pretty good (for me) as it came installed on my i5-based laptop. Mine is Win 7 Home Premium x64.
 
I will add that I do try to shut down basically everything that isn't needed, either through the task manager or the running-apps app in the task tray. My graphics card has an app I shut down, I also shut down my malware app (since I too turn off wireless and am not connected to the internet). Also I close my printer's TSR app. All that jazz.
 
My laptop is a Sony Vaio and has some INCESSANT nagware known as Vaio Messenger/VaioCare installed - and I had to shut down and disable that (it tries to phone home, continually). Same with Windows update - set all that crap to be checked manually so it doesn't try to phone home while you're working on something important in SONAR. Because even if you disable WiFi, it doesn't stop these apps from trying to get out to an update server anyway.

Windows 8 and 8.1 are even better from a performance standpoint.
 
I no longer do any tweaking for any of my DAW software.  I don't even mess around with changing pagefile specifications or disabling internet or antivirus.
 
But I now have a 6-core processor with 64 GB RAM, so I have lots of resources available all the time.  The only thing I still do is keep separate disk partitions, but not for performance reasons.  Mostly just for organizational purposes and to keep my backups from taking three days to complete.  :)

I'm pretty much with every thing riojazz said.
 
I wouldn't bother with changing the Priority to Background Services either.
 
I'm sure many will come on here suggesting all sorts of misguided tweaks.  Just follow RioJazz's suggestions, and run LatencyMon and see what it says.

http://www.native-instruments.com/en/support/knowledge-base/show/752/
 
I like this one......
 
Zap!

Win 7/8 are pretty good, that's for sure, but I still do a little tweaking to the services. For example, if you have Adobe Reader installed, you don't need the Adobe Update service running all of the time. Same with Apple/Google/etc update services, but then again this probably isn't an issue if your DAW isn't connected to a network.
 
And I always disable Windows Search, and Tablet Services (my DAW is a desktop).
 
Like in the link above, I also adjust my power settings and check to make sure the USB power settings aren't allowed to be turned off.

IMO the tweaks and optimisations are mostly a thing of the past.

Good article linked by Zapotek.  However, as I mentioned, that last bit about the background services does not apply to SONAR.
 
Now that Ruben and SubSonic mentioned it, I also delete or disable some services that run needlessly on startup, like Adobe and Apple, if they "phone home".  I don't want anything non-Microsoft running on its own that I didn't ask for.  I don't consider these to be "system tweaks", however, because they involve application software, not system software.  I consider stopping Adobe etc. to be necessary defensive steps when dealing with certain software companies.
 
 

+1 to the posts about not tweaking. Depending on what you do with your machine (and programs loaded), about the only thing I would recommend is running "msconfig" and checking what is in the "Services" (Hide all Microsoft services) and "Startup" tabs. For me, hardware services I leave running (unless utility only), and software services are up to your discretion.
 
Win7 is very stable without tweaking otherwise... the custom power setting of "always on" is a good recommendation as well.