Drive space keeps disappearing from my c drive for no reason. I have windows installed on an 11GB partition. In the last week, free space has dropped from around 1GB to nothing, then back to around 300MB. I can't understand why this is happening, I've installed nothing, disabled system restore and hibernation, and have a fixed pagefile of 250MB (all I need). I use CCleaner but none of the missing space is recovered, windows has eaten over 700MB and I see no reason for this, can anyone explain this peculiarity?