What kind of error your are getting? Check your firewall and make sure it is on and running
Check Windows Security Center and see what is red or yellow(update, Anti-Virus,...)
Do full scan using :
http://onecare.live.com/site/en-us/default.htm and remove all threats
If you don't have Anti-Virus consider to get one such as security essentials
Then go to your email account such as
www.hotmail.com and then click help or forgot password and follow guidance to recover your password.