Are you getting the error with new Deus Ex installation or did you just unzip your game from somewhere? According to Shadowrunner it is a registry error that can be fixed with registry fixing software, although you can probably also try clean installation or repair.
Alternatively try
http://support.microsoft.com/kb/180071/en-us as it might fix the issue. Several SDK users fixed it by manually downloading the missing .dll and placed it in either DX directory or that of windows system folder.