Just picked up UltimateDefrag 1.64. One problem I'm having is I can't get the boot time defragger part to work. My machine boots up without any kind of messages. It's in my registry under the BootExecute key as it should be. Mine looks like this for drive C: UDBDef C UDBDef.exe is in my /system32 folder as it should be. II also have Perfectdisk and that runs fine from BootExecute as does Chkdsk (autochk). Is the entry incorrectly written, perhaps? Is it a problem with permissions? I'm running Vista Ultimate x32.