Hello, I recently installed a registry optimisation programme on my computer, which uses Windows Vista Home Basic. Before the installation, I had around 80GB of hard disk space. After running the programme, I began to get a message saying that the space on my hard disk was very low. I've tried to fix this by erasing files, but any space I gain immediately disappears. I have tried chaning restore points but that has not worked either. A friend told me I should just format my disk/reinstall the operating system, but I am loathe to do that and ruin my laptop for ever. Any ideas?