Whell, the most drastic method, speaking about the contents of the phone, is to flash a complete new MAIN and FS with XS++, but it's effectiveness is the highest. BUT, If you decide to do that, remember to backup EVERYTHING. Get the right versions of the FS and MAIN => the language packages and firmware versions HAVE TO CORRESPOND COMPLETELY e.g. do not use w800 R1BC002 EU_2 FS with w800 R1BD001 APAC MAIN. If you have the right flash files, get some customisation files if you want. If not, just flash first the FS and then the MAIN with XS++ and it's ought to work.