Hello again,

my c drive is in desperate need of defragmenting, i've been trying to use IObit SmartDefrag but when it gets to 69% an error occurs and needs to be restarted!

the error message displayed is-

            The instruction at "0x7c910e03" referenced memory at "0x00746164". The memory could not be "written"

any ideas please...

thanks

The quick answer to your question is to record all the error codes following an error event, also following the error look at your event logs by right clicking on the "My Computer" icon on your desktop and then select "Manage" this will take you to the Administrators tools and there you will find the Event Viewer, find and read any Error events that seem to relate to your problem, also read a few events on either side of the error, sometimes you can find clues, also sometimes there will be a link to the Microsoft Knowledge Base where; if your lucky a fix will be posted, regardless record all pertinent information, Source, Event ID, error codes excetra, you can Google these codes and usually get an answer, it's hard to give a straight to the point answer to most errors since there are almost always several answers to the same problem, just sort thru them and find the one that meets your circumstance. Good Luck

try running ScanDisk

   To answer your question, it looks like SmartDefrag is trying to write to a memory location that it is not allowed to write to.  That could be a bug in SmartDefrag or a bad spot on the drive.
   I would also recommend using ScanDisk.