Imac Hardware Problem

i have imac 27 in mid 2 011 and it had a problem with hard disk and also i lost dvd which i got from apple with that imac , so i connected external hard disk and installed OS x Lion on it now i can logon But ethernet card , wifi , dvd or not working . once i restarted and while booting i hold opt button on keboard and entred into recovery which has got from clean installed in extrnal harddisk , and it worked there , then i restarted and booted into os normaly . it was fine Working . but agine when i shutdown and restarted , i got same issues , and same process ,but dint work .

so cAN any one know this problem

please replay me