SharePoint 2010 can be installed in Windows Vista and Windows 7 if you are running a 64 bit version of the OS. But if you try to install SharePoint 2010 in Windows 7 you will see the following error message.
Guess What installing SharePoint 2010 in Windows 7 or Windows Vista is not easy as it sounds 
There are few settings which you will have to make before starting the install.
Setting Up the Development Environment for SharePoint 2010 on Windows Vista, Windows 7, and Windows Server 2008 is a must read before installing SharePoint 2010 in Windows Vista or Windows 7.
[...] are getting better with SharePoint 2010 and you can install MOSS 2010 in a Windows 7 pc and start developing apps but what if you don’t have a good build or required [...]