cannot mount disk image

[jimbo034]

when ever i try to open a downloaded .dmg file on my ibook it cannot mount the disk image. when i double click on it's icon on the desktop nothing happens for about a minute and then a window pops up saying that "the following disk image failed to mount" and then the file name and then "device not configured".

thanks in advance

 

[eric2006]

Try moving these files to the Desktop, then restart twice and try a .dmg;

/System/Library/Extension.kextcache

/System/Library/Caches/com.apple.kernalcaches/