Does your XP 2600+ have a Thoroughbred core or a Barton core, kkkoolkev.
If Thoroughbred, set the FSB to 133MHz and the multiplier to 16x
If Barton, set the FSB to 166MHz and the multiplier to 12.5x
Don't do the above yet, until you find out which processor you have.
As the multiplier usually defaults to the correct setting are you sure you don't have a XP 2500+ Barton, because both the XP 2500+ and the XP 1700+ (which you say yours is reading as) have a multiplier of 11x, only their bus speeds are different (166 and 133 respectively)?
PS Please try and use some punctuation in your reply.