Rather than relying on the WinXP's time features, I use a program, NISTime.exe, downloaded from NIST Boulder. If your separate PCs have an internet connection you can have them sync with a time server as often as once per hour. Norman, here are the time difference entries in my log for the past 24 hours for my Dell 2350; as you can see some of the hourly differences are under 100 milliseconds but some are 3, 4 and 5 times 100 milliseconds, and the cumulative drift during the 24 hour period is -0.232 seconds net ---Date--- --Time-- Difference (Sec) Year Mo Da Hr Mn Sc Incre. Cumul. 2006 05 23 00 25 13 0.144 0.144 2006 05 23 01 25 13 0.176 0.320 2006 05 23 02 25 15 -0.252 0.068 2006 05 23 03 25 17 -0.080 -0.012 2006 05 23 04 25 18 -0.235 -0.247 2006 05 23 05 25 20 0.213 -0.034 2006 05 23 06 25 22 0.146 0.112 2006 05 23 07 25 24 0.080 0.192 2006 05 23 08 25 24 0.160 0.352 2006 05 23 09 25 26 -0.224 0.128 2006 05 23 10 25 28 -0.138 -0.010 2006 05 23 11 25 29 -0.311 -0.321 2006 05 23 12 25 31 -0.032 -0.353 2006 05 23 13 25 31 -0.049 -0.402 2006 05 23 14 25 31 -0.110 -0.512 2006 05 23 15 25 33 0.039 -0.473 2006 05 23 16 25 33 0.058 -0.415 2006 05 23 17 25 34 0.081 -0.334 2006 05 23 18 25 34 0.116 -0.218 2006 05 23 19 25 36 -0.058 -0.276 2006 05 23 20 25 36 -0.123 -0.399 2006 05 23 21 25 38 0.129 -0.270 2006 05 23 22 25 40 0.093 -0.177 2006 05 23 23 25 41 0.153 -0.024 2006 05 24 00 25 43 -0.208 -0.232 HTH -- Ron McK4, Inc. Orlando, FL