The countdown is finally here — Microsoft is ending official support for three of its flagship products of the early 2000s — Windows XP, Office 2003 and Internet Explorer 6.

Today, April 8, 2004, is the last day that Windows Update will release security, technical or any other fixes for these products. That means that if a hacker finds a loophole — or has been holding on to one for awhile, waiting for today — then Microsoft won’t fix it. That also means that using any of these three decade-plus-old software applications is no longer safe.

Microsoft has a lot more information on this day on their End Support Help Page.

It’s the end of the road for Windows XP.

Internet Explorer 6

Now, there’s a good chance you’re probably not still using Internet Explorer 6. It’s a free upgrade on XP all the way up to IE8, and much of the web doesn’t even function correctly on IE6 anyway. Luddites and other people living in the Stone Age would have been turned off by IE6 aesthetically and gone for the free upgrade. If you haven’t done that yet, go to www.microsoft.com/ie and upgrade — or better yet, try Google Chrome or Mozilla Firefox.

Microsoft Office 2003

Office 2003 is a bit more of an issue. Like a lot of you, I was initially turned off by the “Ribbon” that’s part of the user interface of Office from 2007 onward. But we’ve all had seven years to get used to it, and Microsoft has improved the interface over the years. That said, if you’re still clinging to Office 2003, you’re going to want to upgrade. Historically, old versions of Word have been massive targets for hackers, and it’s a sure bet that Office 2003 (and earlier) will be no exception. Luckily, Microsoft has a cost-effective solution called Office 365: pay a single monthly fee and get the latest Office on several computers and devices at the same time.

To get Office 365, you’ll need Windows 7 and up, though, which brings us to the big one: an operating system upgrade.

Windows XP

It’s really important that you upgrade past Windows XP as soon as possible. It’s almost a certainty that hackers are already readying their best exploits. And with double-digit percentages of the world’s PC users still running XP, we are all at risk. Windows 7 is an easy, inexpensive upgrade for most XP users, unless your PC is very old. If your PC is a little newer, try the more modern features of Windows 8.1 out (and grab our free Start Menu Reviver while you’re at it!)

If you’re not sure if your Windows XP machine can upgrade at all, try out Microsoft’s Windows Upgrade Assistant. You may need a new PC altogether.

For those able to upgrade, we’ve got a guide for Upgrading to Windows 8.1, which covers all previous versions of Windows back to XP.

And here’s another guide to upgrading from XP to Windows 7.

Whichever route you take, your PC will be more secure, and you’ll be safer using it. Good luck!