I swore off April Fool's pranks long ago. But the Wayback Machine still has PC World's Save DOS campaign, a parody of our sister publication InfoWorld's then-current campaign to save Windows XP. Our version included a spontaneous DOS reboot. https://web.archive.org/web/20080424031435/http://www.pcworld.com/ic/savedos/
PC World - Save DOS

@harrymccracken I still have a t-shirt from that! (...somewhere.)
@jr I forgot we offered them and don't even remember seeing one.

@harrymccracken Found it! Only slightly dusty...

I honestly couldn't even say how I came to own it at this point. I must've either ordered it somehow or maybe been given it when I visited the San Francisco office way back when (which would have been circa, oh, 2009 or 2010, probably?).