Quick, someone call the meteorologist that had her forecast interrupted by a Windows 10 nag screen! She’s running out of time to get that upgrade done.Microsoft published a blog post today trumpeting the total number of Windows 10 installs so far. The timing is no accident: presumably they did it now to counter a slew of recent articles claiming that the pace of upgrades had slowed to a crawl.Their response: Windows 10 is already running on 300 million devices, and those are all active devices. That apparently means they’ve all been used in the last 28 days, just in case you thought they might be padding their stats by including systems that had been updated and then shelved.They had one more message to deliver along with their figures: you’d better get your butt in gear if you want that free Windows 10 upgrade because the deadline is rapidly approaching. You’ve got until July 29. At least you have until July 29 as of right now.That’s the date Microsoft had set when they kicked off the program, but their language leaves the door open for an extension. While the blog post says “the free upgrade offer will end on July 29,” ZDNet’s Mary Jo Foley reached out for a comment from Microsoft and was told “the free upgrade promotion is currently slated to end on July 29.”The response has a very different ring to it, and it might make you think maybe… just maybe… Microsoft is playing the infomercial pitch man here. Creating a sense of urgency — and making people feel like they’re going to miss out on a really sweet deal — has been a popular marketing tactic for a long, long time. It’s that whole “call in the next 20 minutes because we can’t do this all day,” schtick.If they aren’t, well, then come July 30th you’ll have to pony up $119 to upgrade to Windows 10 Home.