Idle

set idle priority (almost no action) to current process/thread

Below Normal

set priority below normal (available only under Windows NT/2000/XP)

Normal

set normal priority

Above Normal

set priority above normal (available only under Windows NT/2000/XP)

High

set high priority

Real-time

set real-time priority. Use it with care. It may cause other applications and even the system to stop responding!