January is always a difficult month to do your shopping.
Prices are often inflated and managers are sometimes accused of panic buying in a bid to save their season.
That's not to say Manchester United haven't had a bit of luck in the January sales. Nemanja Vidic and Patrice Evra, who have been regulars in United's defence for nearly seven years, arrived in January 2006.
Swedish striker Henrik Larsson spent three months on loan at Old Trafford after signing in January 2007, helping United on their way to the Premier League title.
Wilfried Zaha was Sir Alex Ferguson's last signing when he put pen to paper in January 2012. He's endured a frustrating start to his United career but has already been capped by England.
But as well as the success stories, United have also had some disasters since the January transfer window was introduced in England ahead of the 2002-03 season.
Here, in no particular order, are some of the worst.