HKLM\SYSTEM\CurrentControlSet\Control\Session Manager

Data type Range Default value
REG_DWORD 0x0 - 0xFFFFFFFF (four-second units) 648000 (648,000 four-second units = 30 days)


Determines how long the system waits for a locked kernel-mode resource to become available. When a resource is unavailable, the system waits for 500 milliseconds. If the resource is still unavailable, the system boosts the priority of the thread using the resource (to speed its completion) and waits for up to the number of four-second units specified by the value of this entry before terminating the request. If the resource becomes available before this time expires, the timing stops, the timer is reinitialized, and the resource is released to the waiting thread.

A resource that remains unavailable for more than 30 days typically indicates a problem that should be investigated and resolved before proceeding.