Normally, only Windows Vista users who bought the retail product would be eligible for free support but, for SP1 installation, even users with an original-equipment-manufacturer copy of Vista on their computer can get Microsoft's help, according to the official Vista blog.
"We are offering free-of-charge support to anyone who is having issues installing Windows Vista SP1," Microsoft blogger Brandon Le Blanc said.
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, which will be answered within one business day; online chat, which has a current waiting time of around 40 minutes; and 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.
Support will be handled on a case-by-case basis, a Microsoft spokesperson said, and the user will always be advised if costs are involved.
Whether enterprise customers will also receive support without cost will depend on their agreement, the spokesperson added.
Suzanne Tindal of ZDNet Australia reported from Sydney.