First I'll recommend starting with this self-help document: [onlinehelp.microsoft.com
That explains how to use the URL normalization tool in Bing Webmaster Tools.
I've seen a handfull of folks confused by the enable/disable fucntions, so I'll try to clarify this here: These features only work if you have a parameter entered to be ignored.
When you first enter and save a parameter, it's "on" meaning we're normalizing any URLs we see with that parameter.
Selecting a check box next to a parameter (or multiple parameters) and clicking the "disable" button will "turn them off" meaning we'll stop normalizing the URLs where we see that parameter (or parameters). The parameter itself remains visible in your account, however, so you can see it, but we're not normalizing against it and it's status is noted as "disabled".
Selecting a check box next to a parameter (or multiple parameters) and clicking the "enable" button will "turn them on" meaning we'll start normalizing the URLs where we see that parameter (or parameters). The status is noted as "enabled".
There are cases where some websites need to be able to turn parameters on and off for various periods of time and these features help facilitate that.
It also means that if you enter 30 - 40 parameters, then need to turn them off, say for testing, you will not need to re-enter the parameters as they will still be available inside your account.
Hope this helps clarify gang.