Nowadays with either Win7 or 8... specifically to have Sonar and its' related programs on one system and everything else on the other?
 
If "yes"...is there a benefit to having separate drives, or just partition the C drive?
 
btw, to repeat, I would consider using the same operating system, and not an older needed one for earlier programs, etc.
 
thx,
Chris

There is not much benefit to booting into one OS with your music applications and another OS with all your other applications. For the most part the programs that are not being used are not going to affect each other. You will use up more space on your drive with duplicate OS installations and will increase the problems of keeping everything updated, scanned for malware etc. In the event that you want to share data between the two OS installations, you will complicate the permissions issues, and possibly introduce problems as one OS is unaware of the changes the other has made to files. And of course you will need to pay for the license for two OS's and possibly for programs installed twice.

My old setup consisted of a dual-boot PC with with 2 installations of Windows XP. Boot1 functioned as the family computer whereas Boot2 was DAW only. Boot2 was a lean installation with only Sonar and plug-ins installed (plus a few essential pieces of other music-related software). It had no internet connection, no virus protection or firewall and fewer background services were running. All unnecessary hardware such as printer and scanner were disabled.
 
Sonar was installed on both boots and it ran noticably better on Boot2. Projects would load in a fraction of the time.

If your DAW is going to be used for general purpose stuff, casual web surfing, installing and uninstalling various programs, shareware and freeware, used by family particularly if they're sharing the login and have administrative rights to install some "free" fancy thing they found in a web search... Then yes!  A Dual Boot will help keep your audio work stable and avoid an "oh crap it doesn't work now" situation.
 
If you can keep control over the OS and who / what it does, then it's not worth it.

Set up a dual boot from VHD (assuming you are not running XP) for your "play" OS and save your hard drive for your "real" install.
Pretty easy to do:
 
 
 If you are running Win8 Pro or better and you are looking for a sandbox to isolate your music pc you can run a VM in Client Hyper-V for web surfing and etc. but that is a bit more of a propeller-head solution.
 
Hope that helps
 
you can go to http:// social.technet.microsoft.com/wiki/contents/articles/516.how-to-boot-from-a-vhd.aspx
 
(remove space before pasting link)

I don't have a problem with a "dual purpose" PC.  However, when I record (or anything with Sonar) I disable the NIC and have system sounds disabled.  That seems to be all that's needed in Win 7 or Win 8/8.1. 
 
With Win XP systems more steps may be needed.  Win 7/8 manages system resources and memory much better.

Deleted.  Dual Post

This is a good idea.
Inside your case you have 1, 2 or 3 HDDs with an install of Windows and whatever other programs and data you work with on a regular basis.
 
Also inside the case you have another 3 HDDs with Windows and Sonar on one, your project data on another, and your samples on the third.
 
All it takes, is for you to unplug the power connector from the splitter that supplies the two configurations, and you have two bootable Windows configurations on different physical Drives.
The only time it takes to change over, is for you to power down the computer, swap power cables, then reboot.
 
I ran this system for a couple of years when using Windows XP, as I had a lot of programs, data and extraneous rubbish that really interfered with my install of Sonar 8. It worked a treat, and took about 2 minutes to swap installs. I tried a couple of other configurations, including dual boot, and this gave me the least problems by far. You don't have to muck about with configuration settings or partitioning of HDDs, it just works (to quote another fruit company).
 
You need to make sure you have enough SATA ports for your HDDs, but this is usually not an issue with motherboards these days. Do your regular install with Windows, regular programs, etc. on your first drives; then power down, change connectors, do your install with Windows and Sonar on your second series of HDDs and you're done. Usually you won't need anything other than Windows and your Sonar stuff installed on your second install, unless there is a program that you particularly need while Sonar is running.
 
The cost involved is only a few extra HDDs. Keep in mind that your C: drive for the Sonar install only needs to be small, as there will be only Windows, Sonar, Sonar updates, and any programs that you need for music production on this drive. The other advantage of this system is that should your everyday Windows install go belly up, you lose none of your music.
 
I suggest any musician building their own computer to look at this option as I can vouch for its simplicity and ease of use.