If you go to 'Control Panel/All Control Panel Items/HomeGroup/View and print your homegroup password' then click on "Print This Page" and you get an error message: error code 2147500037, I have a workaround for it. It appears to be a bug in Win7 and as far as I know MS hasn't addressed it yet.
Anyway the problem seems to be fixed if you make IE the default browser. I got this error and have FireFox as my default. I switched to IE as my default browser and I was able to print. I switched back to FireFox as the default, and now I get the error again.
Go figure...