Those times sparked Hernandez to defend the time trials, which some reports had categorized as taking almost a full day. "The 'super user' profile is not a normal user; rather, it's the user profile that represents the extreme power-user who's working with an enormous data set and a large number of installed applications," said Hernandez. "This user profile is not representative of what most 'regular' users, who typically have a much smaller data set and would therefore experience a much, much shorter upgrade time."

Even so, Microsoft's data showed that so-called "medium" users, those with 70GB of data and 20 applications -- would spend between 1 hour and 40 minutes and 2 hours 50 minutes doing a 32-bit upgrade. (The more powerful the PC, the faster the upgrade, according to Microsoft.) Heavy users, which Microsoft posed as people with 125GB of data and 40 applications, would need between 2 hours and 40 minutes and 5 hours and 43 minutes to do the same upgrade.

Clean installs, on the other hand, were much faster, not surprisingly since no data or applications were retained. A clean 32-bit upgrade took between 27 and 39 minutes, while a clean 64-bit upgrade clocked in at between 30 and 47 minutes.

Those marks, of course, do not account for the time a user would spend restoring previously-backed up data and various settings, and re-installing applications.

Microsoft did not test , even though a clean install is the only upgrade path between those two operating systems. But users who start with XP and migrate to Windows 7 should expect times similar to the "clean" scenario Microsoft benchmarked. Again, those times will not include restore data and settings, or re-installing applications; the latter can be a laborious process, with some major programs, such as Microsoft Office, taking as nearly as long as the operating system to re-install.