Commonly, here at DELL tech support. an error 146 could mean two things, either the hard drive failed or files on specific sectors cannot be read properly. We normally complete the initial diagnostic test, then it will ask you if you would like to continue with the memory test - SAY "NO". Then it would booth to the utility partition and you will have to select test SYSTEM. It will give you 4 options to choose, select CUSTOM TEST, drill down to the hard drive and do the test, if the test pass, then it could mean that reinstalling windows might just be the thing that you need to do, if there are errors that some sector cannot be read, then that would mean hard drive replacement. Call us at 1-800-456-3355 or 1-800-822-8965 and lets find out what needs to be done to resolve your issue.
Dennis - Dell Tech Support