Si,
The windows share permission etc. are a bit complicated. Check the following:
\* Easy sharing is off (Check http://support.microsoft.com/kb/307874/en-us )
\* Make sure your windows firewall isn't blocking file share requests
\* Rightclick the directory you are sharing on windows and choose 'Sharing', choose the 'security' tab and make sure 'everyone' has 'Full Control'
\* Rightclick the directory , choose properties and choose the security tab. Make sure 'Everyone' has 'Full Control'
\* Rightclick the ISO file in the directory, choose properties, choose the security tab and make sure everyone has full control.