For some reason all you see online at the moment is Windows 7 wifi hotspot related topics making you use software like connectify or use the command line to share your internet connection.
However it is very straight forward to do and you can use Windows 7’s Network and Sharing center, avoiding any command line messing and random software installing.
Here are two articles that show you what to do:
Turn Your Windows 7 PC Into a Wireless Hotspot – Lifehacker.com
How To Turn Your PC Into A Wireless Hotspot – Windows7News.com