Unable to load library steam dll!!!!!

[storeretts]

I recently uninstalled steam due to the fact that it would only function in offline mode, but otherwise it ran fine. once i had uninstalled steam and all the relevant games, folders, etc i shut down my computer and tried to reinstall it the same way that i had previously installed it, which was by downloading steam @ steampowered. once i'd downloaded steam again i ran through the set up wizard and and was presented with the finished box saying installation successful. after clicking ok the next box says ERROR at the top left hand side and in the box itself it says Steam.exe (main exeption): Unable to load library Steam.dll) i have run through every troubleshooting step from firewall to router etc. i've got broadband and have been connected to it through all of the above. i've reinstalled and uninstalled steam countless times and nothing has made any difference. it's basically driving me nuts because i haven't installed changed or deleted anything on my computer other than steam plus games etc but where it worked fine before now it won't even connect to steam library! PLEASE HELP!!! cheers.