when i click shut down in start minue, screen just comes blanck and system dose not shut down.it will take 15 min then will be start
This normally occurs when a resource is still running during shutdown, and has not released memory, causing shutdown not to function properly.
1 - Check in event viewer for possible errors.
2 - Did this behavior start after new HW or SW was installed ?
3 - A Windows system restore to date before this started happening
may be in order.