Windows 7: Windows 7 Custom Sound not working

Hello, this is my first thread, and i wanna ask help about it..
ive searched a lot in google and had not found any answers..


My problem is some Custom Sounds are not working..
for example, ive customized Minimize event and change it to an existing Windows Default sound, i press PLAY and its working, hit APPLY then OK..but its not working..
tried it on other events, and still does not work,



the other thing i noticed is
i cant UNCHECK the option "Play Windows Startup Sound" (its greyed out)


I've modified imageres.dll (mainly because of my theme) had edited on my own and had not touch on the wav files..



Please i need help, ive tried imageres.dll on other computer and it plays had no problems with the sound..

up..please i need help on this, any ideas ?