How to CHMOD folder writing permissions during installation???

[Punktured]

so, you are running this locally?
windows as far as i know does not have the same system commands as unix,
so chmod wont work.

i dont know if it would work, but you could try commenting out the file permission check in the install folders index.php script.

as i said, i am unsure if this would work tho, you may still run into problems regarding file permissions.