Yes, same thing happened to me today. I downloaded the manual installer for MSAS from their site, ran the installer and - hey presto! - my Arial font appeared
italic all over the place (mostly in Office), which generated a fair amount of head-scratching and Rough Language.
Thanks to various kindly souls here and at the Other Place, I discovered the cause and how to fix it, although my fix was to uninstall MSAS completely - who needs it?
My recommendation is don't bother with MSAS at all. After 20 years in Unix-based IT, I'm afraid I just have no patience at all with the kind of Windozy hacking that has a "simple" package installation screwing around with your OS folders any more than strictly necessary, even in this relatively trivial manner.
There are plenty of other free WAMP packages that don't mess up your fonts e.g. EasyPHP or XAMPP, and Mambo/Joomla itself is a piece of cake to install (congrats to the developers on that one!), so why bother with MSAS at all?
PS: Just installed XAMPP + Joomla with no problems at all
http://forum.joomla.org/index.php/topic,14555.msg93367.html#msg93367