My 500gb HDD had about 46gb a few days ago. Today my PC was running very slowly. First I removed some new progs I had installed thinking that was the problem, which did speed things up a quite a bit. However, upon checking C drive in Computer I noted I had now got 345Gb on it. I did a 'disc cleanup' but this only removed a few Mbs. I have tried removing shadow copies & all but the most recent restore points. Windows backup is disabled as I have Acronis configured to backup to my 250 slave. I have to confess I am totally clueless on how to use Acronis. Can anyone explain why my drive has tripled it's content in just a couple of days? And how to reinstate my c drive back to it's 46gb? Thanks in advance. Alexma.