Clearing your history and temporary files still might not be giving you enough memory with which to work.

You need to increase the allotment you have given your comuputer for those types of files.

For Windows( I have xp) Click START Click CONTROL PANEL click SYSTEM click ADVANCED click PERFORMANCE OPTIONS/SETTINGS then click on VIRTUAL MEMORY setting of find that... and increase the amount of memory you have set for the computer to store and use. Make sure you CLICK APPLY!

good wishes

PS you might also wish to change (at the same page) the computer to run with PERFORMANCE as it's primary process.