folder permission

Hi

I run window server 2008 with IIS 7.5 without much knowledge on the system but running many websites.

I just entered the world of Drupal since last month.
I read so many posts and Q&A on the net but didn't find the right solution for me.

I install Drupal 7 very well. Site is running fine.
BUT when I go "update module" with update manager...
After downloading files and installing...updating...
I get errors like this-example.

ctools

Error installing / updating