要求された操作を完了できません。メモリ（RAM)が不足しています。という表示が出て、サイズの変更も保存もできません。

Hi 孝子中,

Thanks for posting in Adobe forums.

It seems like you are facing issue with the performance of Adobe Photoshop Elements.

Could you please follow this article for reference.

Please make sure you create backup of your Windows OS registry before making any changes.

Hope it helps.

Thanks

Regards

Dhananjay