This one is for when you get someone saying their connection drops for a couple seconds every now and then, where your options are:

1) Sit trying to fix it while it's not broken.
2) Put this on their desktop and get them to run it when they think they've been disco'd.

echo off
cls
echo hang on a mo...
REM Check localhost
ping localhost -4 -n 1 > c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt

REM Check Default Gateway
ping 192.168.1.253 >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt

REM check File Server
ping 192.168.1.10 -n 1 >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt

REM Check Internet ping
ping 4.2.2.2 -n 1 >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt

REM check dns name resolution
echo NSLOOKUP >> c:\ping\pingtest.txt
nslookup www.tekheads.co.uk >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt

REM print ipconfig
ipconfig /all >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt
echo. >> c:\ping\pingtest.txt

pause

Simple, but dead handy.