hello
i had windows 7 home premium for a long time but i had some pictures by mistake encrypted and after i reinstalled OS now i cant open them,even if i uncheck "encrypt contents to secure data" it says "you need to provide administrator permission to change this atributes" but after i click continue i get "access denied"
is there a way to recover them back ?

Go to the Security tab and then edit permissions so you have full control of the file. Then unencrypt the file.

Have you exported your private keys before you reinstalled the OS? If not, you have to crack it. I did it once with Win2K encrypted files and it was quite fast (minutes), but since then the encryption scheme for EFS was upgraded.

i did and i got the same result

Download this, run the .reg file and then right click on encrypted files and select Take ownership. Then proceed as you will.

i have the reg files with take ownership and still the same result

Does your current account have admin rights?

yes,im admin

You can only read the encrypted files from the installation it was made on or you will need to crack it.
If you could uncrypted the file from another OS by simply taking over ownership it is not called encryption.

What MSFacts101 and GL1zdA said. Without the private keys, you don't have much hope of recovering them.