How can I check a system's availability?

A. Microsoft's Uptime tool, which you can download at http://www.microsoft.com/ntserver/nts/downloads/management/uptime/default.asp , displays basic system-uptime information. This tool can also list all startup and shutdown events, and you can use the /s switch to show the total percent time that your machine has been available. For example, when I type

D:temp>uptime /s

on my machine, the Uptime tool displays the following information:

Uptime Report for: \EAGLE01Current OS: Microsoft Windows XP, Service Pack 1, Multiprocessor Free.Time Zone: GMT Standard TimeSystem Events as of 07/11/2002 15:03:30:Date:         Time:     Event:             Comment:----------    -------   -----------------  ---------------------------27/09/2002    10:54:46  Shutdown27/09/2002    10:56:42  Boot               Prior downtime:0d 0h:1m:56s27/09/2002    13:21:54  Shutdown           Prior uptime:0d 2h:25m:12s27/09/2002    13:23:36  Boot               Prior downtime:0d 0h:1m:42s30/09/2002    08:46:37  Service Pack       Service Pack 1 installed30/09/2002    08:47:50  Shutdown           Prior uptime:2d 19h:24m:14s30/09/2002    08:52:57  Boot               Prior downtime:0d 0h:5m:7s01/10/2002    08:45:22  Shutdown           Prior uptime:0d 23h:52m:25s01/10/2002    08:50:30  Boot               Prior downtime:0d 0h:5m:8s02/10/2002    10:46:07  Shutdown           Prior uptime:1d 1h:55m:37s02/10/2002    10:48:38  Boot               Prior downtime:0d 0h:2m:31s03/10/2002    08:52:48  Shutdown           Prior uptime:0d 22h:4m:10s03/10/2002    08:58:31  Boot               Prior downtime:0d 0h:5m:43s04/10/2002    15:56:58  Shutdown           Prior uptime:1d 6h:58m:27s04/10/2002    16:02:47  Boot               Prior downtime:0d 0h:5m:49s07/10/2002    13:23:54  Shutdown           Prior uptime:2d 21h:21m:7s07/10/2002    13:25:46  Boot               Prior downtime:0d 0h:1m:52s10/10/2002    14:55:03  Shutdown           Prior uptime:3d 1h:29m:17s10/10/2002    15:01:13  Boot               Prior downtime:0d 0h:6m:10s11/10/2002    09:19:20  Shutdown           Prior uptime:0d 18h:18m:7s11/10/2002    09:21:08  Boot               Prior downtime:0d 0h:1m:48s28/10/2002    09:24:07  Shutdown           Prior uptime:17d 1h:2m:59s28/10/2002    09:26:48  Boot               Prior downtime:0d 0h:2m:41s07/11/2002    08:22:25  Shutdown           Prior uptime:9d 22h:55m:37s07/11/2002    08:24:18  Boot               Prior downtime:0d 0h:1m:53sCurrent System Uptime: 0 day(s), 6 hour(s), 39 minute(s), 12 second(s)Estimate based on last boot record in the event log.See UPTIME /help for more detail.-----------------------------------------------------------------------Since 27/09/2002:           System Availability: 99.9287%                  Total Uptime: 41d 4h:26m:24s                Total Downtime: 0d 0h:42m:20s                 Total Reboots: 12     Mean Time Between Reboots: 3.43 days             Total Bluescreens: 0

Notice the final summary, which displays useful information such as the number of total reboots and the mean time between reboots. You can use the /d: switch to generate statistics from a certain date or use the /p: switch to generate the statistics for a certain number of days. The /help switch provides a description of all available options.