[Kazuki Araya]

first it running fine..until i use the rectangular option, that when the Photoshop not working.

Hence my above comment:

When you start utilizing It, It'll (obviously) consume a lot more.

It seems as though you may require additional Ram, but to be conclusive It's not Adobe Photoshop causing the Issue per se, run It In a system with sufficient available Ram. If It functions properly thereafter, It's your system that needs attention.

It seem so mothered. Next month i will buy another 4GB RAM for Adobe Photoshop purpose. If my company resist do not want to buy the additional RAM, I will buy it for myself. Just for the IT Department.