When I installed Windows on my MacBook Pro, I allocated a 20-gigabyte partition. It turns out 5GB would have been enough. The Mac drive, on the other hand, is almost full. Is there an easy way to reduce the Windows partition? Name and address supplied DQ: Depending on what system you are using, Mac OS X is supposed to allow you to reorganise your hard disk in a so-called 'non-destructive' resizing. However, if you begin to fool about with disk partitions, you must back up everything. Buy a new disk - then you can begin to experiment. You can use Apple's own tools or you can buy third-party software, such as Data Backup 3 for Mac from ProSoft Engineering (prosofteng.com). It also offers Drive Genius 2 for Mac, which it claims can repartition your disk 'on the fly'. You once wrote about Macs that won't start. I have this problem and have no idea what to do. Tim, Discovery Bay DQ: I am sure this issue will keep occurring. Pop the original DVD-Rom into the disk bay and reboot. If your machine does not boot from the DVD-Rom, start again and hold the letter 'C' down. After the first screen, go to the menu and click on 'Utilities' and release the mouse on 'Disk Utility'. When this application starts up you will see a number of disks connected to your system on the left. Choose the disk you are having problems with then click on 'Repair disk'on the right. You may want to click on 'Repair permissions' too. Once you have done that, you can reboot and see if all is well. Obviously, if you have something like Time Machine running, you can access that and restore the last image it made of your system. You can also hold down the command key plus the letter 'S' when you boot and you will get a black screen with a lot of writing on it. Once you get the prompt, type 'fsck - fy' (exactly like that). Wait for it to say 'File System was Modified' then do it again. Keep doing this until the message reads, 'No problems were found'. You can then type 'exit' or 'reboot' and see if your machine is back to normal. If that does not work, you may have to reinstall the operating system.