Could also be talking about your page file. Unless you set the size manually yourself windows sets the max size of your page file aka disk space it uses as a type of RAM and sometimes it does not set it anywhere near large enough. Windows 7 has the reverse problem and it sets a monstrously large page file that it can never use.
General rule is that your page file should be 1) mostly on a different drive than your boot drive, 2) a maximum of 1.5 times larger than your RAM, and 3) in increments of 250. The min dump file that can be offloaded to the page file is 250MB. That being said you should have a very small page file on your boot drive and the rest on another as seen here.
WIth 8GB of RAM you are looking at a min page file of 8250MB and a maximum of 12250MB. For referance I set my computer back to system managed size and I created a very small page file of 1856MB in comparison to the 12250 I usually have it set at. Getting into more advanced modalities there are windows experts that say to use the max usage, peak commit, - physical RAM formula for the min and double that number for the max.
This takes into account the idea that your cpu will nearly grind to a halt if it is processing the full usage of your RAM and a large page file. While this is true you would have to go to the effort of finding out what your peak commit is and well most people would not want to go to that effort considering we live in the age of terabyte drives.