How can I test the latency of a Windows network?

Dudes:

I have a customer who is failing to connect more and more frequently using our product. My theory is that a timout is occurring because the network is busy.

How can I test that?

Thanks - rev

There are network testing tools/software that do this, but a simple ping will tell you if there is too high latency and packet loss.

I've seen this app mentioned quite a lot on forums: http://www.visualroute.com/

How would I know from the results of a ping whether it was quick or slow? It's going to be expressed in milliseconds, right?

Could this also be due to a router bottleneck?

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\XXXXXX>ping www.yahoo.com

Pinging www.yahoo.akadns.net [66.94.230.48] with 32 byt

Reply from 66.94.230.48: bytes=32 time=2765ms TTL=47
Reply from 66.94.230.48: bytes=32 time=116ms TTL=47
Reply from 66.94.230.48: bytes=32 time=59ms TTL=47
Reply from 66.94.230.48: bytes=32 time=196ms TTL=47

Ping statistics for 66.94.230.48:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss)
Approximate round trip times in milli-seconds:
Minimum = 59ms, Maximum = 2765ms, Average = 784ms

Notice the first time listed. That was caused by my firewall but the other 3 are within limits.