i have installed vb 4.0.3 at http://it-pk.com/forum/ but neither login nor regester system is working
i did a test, didnt work. you may wanna check the php and mysql versions on your server first if they meet the minimum requirements. if thats ok then try restoring the default for all the templates. let us know how it goes.
Can you provide a screenshot of your settings at AdminCP > Settings > Options > Cookies and HTTP Header Options Path To Save Cookies should be just a "/" Cookie Domain should be "(blank)" Add Standard HTTP Headers should be set to "No" Add No-Cache HTTP Headers should be set to "No"
i am just a beginer. but at the time i installed i was able to login. but still i can login to admin panel via /admincp