Hello, hog rider 06.
Thank you for visiting Apple Support Communities.
You will need to access the menu bar and select Store in order to authorize your computer. The placement of the Menu and Sidebar are hidden by default in iTunes 11. To enable the menu bar to access the store menu to authorize the computer, press Control-B. To enable the Side Bar, press Control-S.
iTunes: Turning on iTunes menus in Windows 8 and 7
http://support.apple.com/kb/HT5610
iTunes Store: About authorization and deauthorization
http://support.apple.com/kb/ht1420
If you are processing these steps and repeatedly asked to authorize your computer, see the steps in the article below.
iTunes repeatedly prompts to authorize computer to play iTunes Store purchases
http://support.apple.com/kb/ts1389
Cheers,
Jason H.