If your commuter has SATA connections, which if it's not more than 5 years or so old, it should, get a SATA hdd. They're easier to install plus the newer Intel boards only have connections for 2 PATA drives. With SATA there is no Master/Slave. Even if you want to use the new one for your OS, I'd install it initially as a back up, foramt, and partition it and copy your data over to the new drive onto the partition that you will not put the operating system on. Then take out the old drive and install Windows and then reinstall the old one as a backup. If you're going to use the new one as the backup. just install it. If you don't have the power connector and data cable, you can order them when you order the drive. You can look at your PSU and see if it has any SATA power connectors and the data cables would have come with the computer or the mobo if you put it together yourself