Backup your files before using it.
Here is the release candidate 1 of romcenter 3.  
 
This version was destined to be the final version, but some last minutes bugs make me change to this release candidate.
 
 Bugs fixed:
 - 'Open path in explorer' enabled on datafile node
 - 'Clean db' disabled on some nodes
 - listview not refreshed after a 'close db'
 - 'check drive' disabled on some nodes
 - 'rebuild all' removed (not used)
 - Listview not cleaned after loading a new db
 - Some menu falsely enabled after loading a db
 - Custom emulator command lines not saved
 - parentnode button enabled when no node selected
 - db error 'multiple rows in singleton select' 
 - fix some log messages
 - folder size = 0
 - cursor pointer not always set to hourglass
 
 Features added:
 - New generic xml format
 - 'Short path name' option to display short paths in view
 - Name of database in main treeview node
 - Zipped CHD detected
 - 'Samples mode' info in statusbar
 - Several options disabled if not avail in database (chd, samples, bios...)
 - DB nodes hidden if not avail in database (chd, samples...)
 - Search box is back
 - 'remove useless files' no more by default
 - 'create ghost games' by default
 - DB info set when creating a mame database
 - French translation (still incomplete)
Reports bugs and comments in the 
dev forum.
 
 Windows installer version : 
 - unzip in a directory
 - run rc300rc1.exe
You can install this version over the previous one.
 
 No installer version :
 - unzip in a directory
Enjoy