The operating system will be offered as a download through Digital River, a company which specializes in downloadable software, on October 22. Copies are restricted to one download per email address and you'll have to choose between the 32 OR 64-bit versions. Not sure which one to get? Be sure to read our guide explaining the differences, and also our recent tip detailing the available Windows 7 upgrade paths.
If you accidentally downloaded or activated the incorrect version, though, you may still contact digitalriver.com for help; and additionally there's the option of ordering a backup DVD with both versions. Microsoft has set up a special web site for this deal at win741.com, where you'll be able to catch all the details. Comparable offers for students in several non-US countries will reportedly follow soon.