hello, i just bought a hp pavilion p6243w and so far i love it. i wanted to do some minor things to it like install a tv tuner among other things but the first thing i wanted to do some put a second hd in it.i been looking up on it n i was told i can make it a slave drive but hp desktops may not allow it. how can i find out the gb capacity for my computer and am i able to do this. im new to all this. thanks
There is no such thing as Master and Slave in SATA drives, so don't be misled. There is no such thing as a Master drive for the whole machine and a bunch of Slaves, but people use those terms sometimes. It would be better to use the term "boot drive" for the one that has your operating system already installed on it, and called C:. Then any added drive can be called a "data-only" drive, in the sense that it cannot be used for booting the machine.
Your computer's manual shows that there is space within its hard drive mounting cage for 2 or 3 HDD units, and the mobo has 4 SATA ports for connection. Probably one SATA port is used for your current C: drive, and maybe a second for your optical drive (or maybe it's an IDE device). Anyway, there certainly should be places to mount and connect a second HDD unit. You will need a SATA data cable, and a SATA power supply connector from the PSU for the new drive. If there is no spare SATA power connector, check with a computer shop for an adapter - could EITHER be one that converts a spare 4-pin Molex connector to SATA, or one that makes two SATAs out of one.
When you get the new unit installed, read the instructions for how to prepare a new empty drive for Windows to use - it will NOT just run right out of the box. There are two steps - Partition and Format - that need to be done. You can do these manually using Disk Management built into Windows. Or you can use a free utility provided by your disk maker to simplify the job of "initializing" the HDD. If that does not come with the HDD on a CD, then just go the the maker's website and download the tool for free.