Windows sounds

Can the Windows sounds be changed? In the WINDOWS\MEDIA file there are subfiles (like RAGA, et.al.) that I would like to try.
But I can't overwrite the default sounds with these subfile sounds since I don't have privilege.
Any help?

If you mean sounds for things like errors, questions, device connected, etc, then just search control panel for "sound", the dialogue box that opens should list things like Playback, Recording, Sounds. on the Sounds tab you can choose a sound then click "Browse" to find a sound file you'd like to use.

However the startup sound is another matter... Startup Sound - Change in Windows 7

That worked. Thank you.