When I tried to upgrade my Office 2003 in one of our XP machine I got the following error message:
"Microsoft Office Professional 2010(TEchnical Preview) encountered an error during setup. Error 1327. Invalid Drive F:\"

Though there was an error during the setup, luckily Office 2010 got installed.
I feel that the error occured while upgrading the office 2003 to 2007, because of that I have both the softwares on machine.
I hope this will be fixed in the actual version of the Office 2010...
I even tried upgrading Infopath 2010 and got the similar error as shown in the following images.
Here also Infopath installed successfully though there was an error during installation/setup.