Visual C++ must be registered within 30 days. A Windows Live ID is required for registration, but it is free and will not spam you.
Inside Visual C++, go to Help -> Register Product. Click Register now. 
If you have a Windows Live ID, type in your email address and password and click Sign in. If not, click Sign up now and follow the onscreen instructions. Remember to uncheck the "you may contact me by email" boxes when signing up to avoid spam.
When you have completed signing up for a Windows Live ID, return to this page by following the register now link in the previous step, then sign in with your new ID.
Copy the 14-character registration key. 
Inside Visual C++, to go Help -> Register Product, paste the registration code, and click Complete Registration.
Note: This screenshot was taken with Visual C++ 2005. The procedure is identical in 2008. Yes, I know this is not the same key as from step 15. Your keys will match.
Select No, I would not like to participate and click Close.
Installing getopt