I dont think she did that tweak that speed up the shutdown process.
To solve the screen flashing and not responding error in windows 7, go to start, type regedit in the search line and press Enter. Once the registry editor is opened, find these registry keys and delete them.
* HKEY_USERS\.DEFAULT\Control Panel\Desktop\HungAppTimeOut
* HKEY_USERS\.DEFAULT\Control Panel\Desktop\WaitToKillAppTimeOut
* HKEY_CURRENT_USER\Control Panel\Desktop\HungAppTimeOut
* HKEY_CURRENT_USER\Control Panel\Desktop\WaitToKillAppTimeOut
* HKEY_CURRENT_USER\Control Panel\Desktop\WaitToKillServiceTimeOut
Once all these keys are deleted, Screen flashing will be solved in your computer.
Should I still do the above method ?