Normally, an unexpected popup is a reason to worry: is my PC infected with a virus? Is this an ad? In this case, yes, you’re supposed to worry—but the message is legit.
In its ongoing bid to push users from Windows XP to Windows 7 or Windows 8, Microsoft will push a popup to their machines on March 8. But the company has also partnered with LapLink for a free migration tool to assist with the transition.