I wrote an answer to this over at Modaco.
See here for the answer to your question.
...or I'll just cut and paste it again here:
For this solution, I'm going to assume you're using Vista. (If you're on XP, then the only major difference is that you use ActiveSync instead of Mobile Device Center). This isn't the only solution, but is pretty "idiot-proof" so it should be fairly straight-forward and easy to follow
1) Get yourself a file explorer for your phone
that is able to overwrite rom files. The one that comes with the phone DOES NOT do this. This is a necessary step. I recommend Resco Explorer. It comes with a free trial. You can get it
here
2) Plug your phone into your computer and open up Windows Mobile Device Center (this does not come with Vista and so you may need to do some basic googling to find it if you don't already have it)
3) Once Mobile Device Center detects your phone, click "Connect without setting up your device"
4) Mouse over "File Managment" and then click "Browse the contents of your device"
5) A new file explorer window will open showing the 2-3 storage devices on your phone
6) Make sure you can see hidden files by clicking the Organize Button -> Folder and Search Options -> View Tab -> Click the "Show Hidden Files and Folders" button. Click Apply
7) Open the \Windows folder in the main device storage (NOT My Storage). Be patient. It can take a minute or so to populate
8 ) If not already sorted, sort the contents of the folder by clicking the "type" sort button
9) Scroll down to the "Wave Sound" files that are now grouped together
10) Find the sounds you want to kill by double-clicking them and listening to them on your computer. (To fully disable the low battery beep and full charge notifcations, you'll need to disable 3 .wav files: Alarm2, phonelowbatt, and Notify - but you can use this method to kill any sounds you don't want)
11) Download the "blank.wav" file attached to this post (
go get this over at the Modaco post I linked up to above)
12) Rename this blank file to the EXACT same name as the file you want to replace. Same spelling. Same punctuation.
13) Drag and drop this newly renamed file into the file explorer window into a location OTHER THAN THE WINDOWS FOLDER (hint: it won't let you put it there). I usually just dump them in the "My Storage" outside any folders
14) Repeat steps 12 and 13 for every .wav file you wish to replace. Make backup copies of the wav files you plan on replacing. You can disconnect you phone from the computer now as you are finished with Mobile Device Center
15) Open Resco Explorer on your phone and navaigate to where you dumped the renamed blank files
16)
Click/Tap and hold on top of the renamed blank file until the menu comes up with the option to "cut" and then cut it
17) Navigate back to the Windows folder in the root directory (again, NOT the Windows folder in "My Storage")
17 ) Don't actually go into the Windows folder. Instead,
click/tap and hold on top of the Windows folder until the menu comes up with the option to "paste" and then paste it
19) If all was done properly, you should get a warning asking if you want to overwrite the file in question. Say yes.
20) Repeat steps 15-19 for each file you wish to overwrite. Once finished, all annoying sound files will have been replaced by blank sounds, thereby silencing them
A little lengthy of an explanation, I know. You can usually do this in less steps if you already know what you're doing, but I'm not sure how much you know about any of this so I figured better safe than sorry
Good Luck!