This one is specific for the 4550...
http://support.dell.com/support/dow...gen&releaseid=R47861&formatcnt=1&fileid=56489
As is this one but it is newer so try it...
http://support.dell.com/support/dow...gen&releaseid=R47861&formatcnt=1&fileid=56489
http://support.dell.com/support/dow...gen&releaseid=R47861&formatcnt=1&fileid=56489
As is this one but it is newer so try it...
http://support.dell.com/support/dow...gen&releaseid=R47861&formatcnt=1&fileid=56489