Unlimited installation and compatibility support is available at no charge until March 18, 2009, according to the Microsoft Service Pack 1 support site.
There are three options available under the free support plan for U.S. users:
- E-mail support -- will be answered within one business day.
- Online chat -- has a current waiting time of around 40 minutes.
- Call -- available only for users who have a software-assurance agreement, professional contract, TechNet subscription, or MSDN subscription, or for those who come under the Microsoft Partner Program.
FYI -- The toll-free call-in number in the U.S. for Vista SP1 help is 1-866-234-6020.