i have win XP 128ddrRAM 40gbhdd intel P4 STILL  ido not install any big software in cdrive , 51% empty space in cdrive (where  my os is ) but still i have allways get an message prompt that "your virtual memory very low " how can i ruldout this !You may need to increase the size of your Virtual Memory..

See here..

Good luckActually, don't increase your virtual memory. That won't really help anything. Instead buy some more ram.
128mb of ram is barely enough to run windows xp. I recommend 256 at the very least and 512MB should be a good amount for most programs. www.newegg.com has good deals on ram.
Virtual memory is almost like a partition on your drive. Infact, Linux creates a whole ENTIRE separate partition for virtual memory called a swap partition.  In windows, this file is called pagefile.sys. A general rule of thumb is to have the virtual memory set to 1.5 times the ammount of ram in your sytem. So if you had 1 GB of ram, 1.5 GB of virtual memory would be ideal. Increasing your virtual memory above the reccomended ammount would create thrashing and not help your system with speed at all. Buying another stick of ram as michaewlewis said is the best SOLUTION. You won't be disapointed in this investment!!You should buy more ram at least 512mb. but you can change your virtual memory (page file) by going to Control Panel >System>Advanced. under performance click settings then the Advanced tab. under virtual memory click change. be carefull. hope this helped Yeah, definitely upgrade to more RAM. 128MB is extremely slow. Go with 512MB or higher. (not that I'm adding anything to what everyone has already said) I always seem to post to late......  thanks , well i know it ,but i thought that there is  any other way to solve this problem , yes im going to buy another stik
once again thanks