In case you don’t know this, go check your AppData/Local folder. You’ll see something like this:
These folders, located speciffically on “X:\Users\USER\AppData\Local\”, are empty and have random names, and if you don’t want to risk messing with the AppData folder, let me tell you that is completely safe to delete these folders.
These are created every time we open any Windows Live service (Messenger, Writer, Mail…), or at least it happens from the Version 2011 (Build 15.4.3508.1109) to latest, Version 2011 (Build 15.4.3538.513).
The problem, apparently, is that Windows Live services are not placing these temp folders on the Temp folder, instead, these are being placed by mistake on the Local folder by error. This, although is a problem, cannot be fixed. Each time you open and close any service, a new empty folder will appear.
But don’t worry, you can safely delete them without any risk since these are only created to store a file of 1Kb of size for almost a second, and then the file is deleted and these remain empty. I recommend you to do it at least once a week to maintain you system clean and organized.