Another test, it seems constant most of the times, don't know probably you have some router problem, are you behind some reseller??
C:\Users\----->ping google.com
Pinging google.com [209.85.135.99] with 32 bytes of data:
Reply from 209.85.135.99: bytes=32 time=110ms TTL=43
Reply from 209.85.135.99: bytes=32 time=108ms TTL=43
Reply from 209.85.135.99: bytes=32 time=109ms TTL=43
Reply from 209.85.135.99: bytes=32 time=124ms TTL=43
Ping statistics for 209.85.135.99:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 108ms, Maximum = 124ms, Average = 112ms