also note, unless i am wrong your .net versions installed (if there are more than one) will all need to go back on, i.e say you had
.net v1
.net v2
.net v3.5
etc, if you want to get back to your old state all those versions would go back on, its not like other programs where the natural assumption is install version 3.5 and that will have all the stuff from v2, v1 etc nope
some of your programs may look for ver 1.1, some v2 and others v3.5 - if it cant find the one it needs you would need to install it, the other versions wont do
all of the above you might want to verify from that microsoft link as i dont have any knowledge on how the .net frameworks operate (and its too late at night for me to read that MS page!!! i need sleep)