I recently tried my hand, once again, at installing another WordPress multisite/network on a Windows machine, but this time using subdomains instead of directories for blogs. The process was identical to my first time around, but a common problem arose once I got the network successfully set up – I couldn’t login to any of the subdomain blogs. It was a never ending looping of redirects that made it impossible to access the admin pages of any of the newly created blogs.
Despite it being a common problem, none of the common solutions seemed to work (clear cookies, change siteurl, etc). But adding this bit of code to wp-config.php did the trick:
Hope this helps somebody else. Thanks to the folks on this thread on the WordPress forums.