I use Centos 5 and plesk 8.4.0, and i made: 1) wget http://3es.atomicrocketturtle.com/installers/atomic.sh 2) sh atomic.sh 3) nano /etc/yum.repos.d/CentOS-Base.repo 4) [atomic] name=Atomic Rocket Turtle – $releasever – Atomic PSA-Compatible RPMS baseurl=http://www.atomicorp.com/channels/atomic/centos/$releasever/$basearch [plesk] name=Plesk Server Administrator baseurl=http://www.atomicorp.com/channels/plesk/latest/centos/$releasever/$basearch gpgcheck=0 5) yum update 6) restart At plesk webadmin, plesk version is psa v8.4.0_build84080514.18 os_CentOS 5