If you get a window that pops up when starting prevail that says "Browse for folder" and repeatedly ask you to find the Prevail client folder, check to see in regedit if the local path's are looking for the same folder as the prevail short cut on the desktop, and the shortcut in the start menu. if they are all pointing to the same directory, browse to the prevail server folder, open the file updates , and copy the whole folder, then go to the Prevail_Client folder and copy & replace all the folders in that file. Prevail should work after this.