Thanks.. As you said I installed the new repos .. and installed QT mobile hotspot and Mobile Hotspot .. but when i start the hotspot no wifi signal is turned on.
Ok, possibly you need "Linux kernel for power user" on your phone.
1. de-install "Mobile Hotspot" (you need QT Mobile Hotspot, only);
2. please de-activate ALL devel-repositories (they are dangerous!);
3. install "Linux kernel for power user" via Application Manager;
4. Reboot your N900 and check ist again.
As I said earlier .. when i touch the start button in qt mobile hotspot it says hotspot successfully started but it does shows a wifi signal. so,that i cannot recieve a wifi signal from another phone. but qt hotspot running in background.
Sometimes, there are devices which can not receive this WEP-Signal from the N900. My girlfriends Windows-Phone don't receive it, for example. My Laptop get it.