I want to upgrade to OpenAT v3.02 so I wanna remove v2.10 is there a reliable method to remove all OpenAT and Cygwin from computer?
my suggestions:
1.unintall 2.1 version, delete cyqwin
(I think deleting the registry entries is hopeless)
2.install open at 3.02 with everything, select “install all” for cygwin,
do not use space in cygwin and in Open At path (and other tricky characters as well)
If some script error comes up with project wizard, look into the docs.
3.pray 
tom
no need to pray
I installed it at the 2nd step 