1. Have you made any changes to the computer prior to the issue?
2. Do you get any specific error codes?
A pool header issue is a problem with Windows memory allocation. Device driver issues are probably the most common, but this can have diverse causes including bad sectors or other disk write issues, and problems with some routers. (By theory, RAM problems
would be suspect for memory pool issues).
Disconnect any external devices connected to the computer except the mouse and keyboard, check what happens.
With Windows 7, you can run a check disk from system recovery options using command prompt.
Refer the article mentioned below:
What are the system recovery options in Windows 7?