If your hardisk is split into several disks, make sure that the disk where Windows puts its virtual memory swap file has at least as much free space as the size of your PCs internal memory. Windows needs to be able to swap all memory to disk, in your case 512Mb. Next to that, its recommended to save space for 2 times your internal memory as Windows will try to use this much disk space for its virtual memory, 1Gb in your case. Should you want to handle the virtual memory size yourself, set the min. size to 512Mb, max. 1Gb. And have windows put the virtual memory file on a disk that doesnt get too much fragmented, so dont put it on a disk with lots of images and other small files that get frequently changed. Confused? I am. Maxx ;-)