Modifying registry to increase GPU timeout, windows 7

The link in your post is correct, you just need to create the corresponding key with the desired value. You will find the TDR Registry Keys description here. The setting you are looking for is

TdrDelay
Specifies the number of seconds that the GPU can delay the preempt request from the GPU scheduler. This is effectively the timeout threshold. The default value is 2 seconds.

KeyPath   : HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\GraphicsDrivers
KeyValue  : TdrDelay
ValueType : REG_DWORD
ValueData : Number of seconds to delay. 2 seconds is the default value.

What you need to do is to create a new key named TdrDelay of type REG_DWORD under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\GraphicsDrivers and set its value to what ever you desire (value in seconds). After that you need to restart your computer for the setting to take effect.