Looks like you don't have enough memory.
Make sure you don't have anything spurious running in the back ground by checking your Start Up file.
Click Start and type: msconfig. It will appear at the top of the list and you then click on the Start Up Tab. Disable anything you don't think you need. If you are unsure about a process then Google it before disabling it but in general terms it shouldn't stop you running even if you 'disable all'.