haven't tried it, but it would not surprise me if it went either way of working or not.
obviously win7 wasn't out at the time sonar 4 was released so there could very well be a problem with it running especially if win7 is the 64bit version. 32bit version of win7 might run it without problems. or it might not...
does your soundcard/interface have win7 drivers? that's where I'd start troubleshooting it.