Although many people who have had issues are on Windows 7, I do not fully believe Windows 7 is the problem. I started a wallet and I'm solo mining through the wallet on Windows 7 without problems.

The only problem I faced was the default nodes were not allowing for connections. However, after adding the nodes others have posted into the config file, I have had good success. On both my Windows 8 and Window 7 wallets, I currently have 7 active connections, which is plenty to allow the wallet to fully operate.

I did notice however, when setting up the wallet on Windows 7, for the first hour or so I only had 1 active connection. I have let the wallet run throughout the evening and now have 7 connections. It is as if it just takes some time establish connections. It is sort of strange.