possible reasons: 1. pro-active function of kaspersky... when it is turned on it slows down programs... because it scans it for possible vulnerabilities.. 2. briscopack... or other same like programs to cuztomize the gui of windows xp... sometimes not compatible to programs such as photoshop... 3. there was an installation error... or some files are missing... try to re-install it... 4. memory allocation... 1G memory is the recommended ram to keep photoshop running..