if you have small memory on your computer (server), the best solution is to adjust SQL Server memory and make it FIXED

so in Enterprise manager do this:

1- right clcick on your server and choose (properties)

2- go to memory tab 

3- check on (use a fixed memory size) and alocate it in trackbar under it ... and a number is writen beside (use a fixed memory size) indicate how much memory you use

4- do not check on (Reserve physical memory for SQL Server)

by the way you can change (Minimum query memory) to 512 if you need, but it is not recommended.

i hope this help u