Turn Win 7 laptop into a wireless hotspot?

i have been trying all software that deal with internet sharing via wireless adapter, ranging from Connectify, VirtualAP, Dell Laptop to Hotspot Converter and some plenty more but I still fail to get the effect i need. am using Dell Latitude D63o with Win 7 Ultimate SP1 installed, for my internet am using a Huawei E220 3G Modem provided by Zain (now Airtel) with unlimited access. When I tried using Connectify, it kept on conflicting with the modem drivers, the remaining software don't seem to find my internet connection, I only get a '' on the internet connection display box so i cant share a connection through any of the remaining software. using Windows 7 Adhoc networking is also so inconvenient because whenever i protect my connection with a password, other computers fail to establish full connectivity ( i only manage to share internet connection when the connection is insecure). Please help in finding a software to turn my windows 7 laptop into a wireless hotspot hosting an encrypted connection and capabilities for other computers to establish full connectivity.