Fix a bug in Wordpress CMS running on Windows server 2003

My website is running on Windows server 2003 VPS with IIS 6.0. My current custom posts are unable to use "Pretty Permalinks", it only able to use "Almost Pretty permalinks", ie: "[login to view URL]". This probably due to windows server. I am also having problem unable to change the files & folders permission from 0666/0777 to 0644/0755. I am also having [login to view URL] file with follows errors: PHP Warning: PHP Startup: Unable to load dynamic library 'C:\Program Files (x86)\PHP\v5.3\ext\[login to view URL]' - The specified module could not be found. in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library 'C:\Program Files (x86)\PHP\v5.3\ext\[login to view URL]' - The specified module could not be found. in Unknown on line 0 Beside the above, my website is running well except a bit too long to load. My site also require to allow login by our vendor to see some of our products info that not for public, but I don't want our vendor to access to admin panel / dashboard. However we want to allow them to change their password of their choice. I try some plugins but it do not work. I also need to improve my security of my media library that do not allow public to enter url to access to our files without the need to login as a user. I have add a [login to view URL] file into every folders in my media library but pubic still can enter the url to access our file if they have the file name. All the above may due to errors created during setup. So we need wordpress / windows profession to solve my issues above. You do not necessary able to solve all of the above issues but you need to let me know which issues you can solve it and the cost to do it. Do let me know what other details you require.