Navigate the the location below in your registry and make the corresponding change.

Create or edit the existing DWORD value (string value for Windows 98) named "KeepAliveTime" and set it to the number of milliseconds to wait before sending keep alive packets (the default is 2 hours - 7,200,000 milliseconds). 

Also create or edit the existing DWORD value (string value for Windows 98) named "KeepAliveInterval" and set it to equal the time in milliseconds between retransmissions of keepalives, once the KeepAliveTime has expired (the default is 1 second - 1000 milliseconds). 

Also create or edit the existing DWORD value (string value for Windows 98) named "SessionKeepAlive" and set it to equal the time in seconds between keepalive packets on active sessions (the default is 3600 second - 1 hour). 

Restart Windows. 

Key:[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP]
Value Name: KeepAliveTime, KeepAliveInterval, SessionKeepAlive
Data Type: REG_DWORD