i recently had windows 7 with 2 partians on my 500gig sata hd and i decided to install windows xp, for some reason it shows the hd is only half its size ive deleted the partians in computer management ive formated it everything it shows up in windows 7 as 500 gig free but 250 gig free in xp could someone please help
Yeah, you may wanna check that out. Apparently XP installs prior to SP1 need a boot floppy in order to install XP on SATA. Maybe something mucked up and let you get through. Odd. If you don't have any important data on there, you might wanna download a program like Darik's boot n nuke (search on Google) which will format your drive. It has fixed a number of faulty drives that couldn't install stuff properly - you may wanna give it a shot, as it's worked wonders for me.
EDIT: Sorry, it's not a program - it's an .iso that you burn to disk and boot off. Whoops.
SP1 is not your issue. The original XP did not support 48-bit LBA and that needed SP1 or later to fix. But the symptom was that original XP could only deal with a HDD volume of 128 GB or less, not 250.
You appear to be aware of the differences between Partitioning and Formatting. But just to be sure, are you positive that the two Partitions were deleted? Or, did you just delete all the files on the Partitions and leave them as blank Partitions?
I assume what you are trying to do is a complete new install of Windows XP as if the HDD were completely empty. There are two steps to preparing the HDD for this, and the Install Disk normally helps you do this by nearly hiding the details. Step One is the create a Primary Partition on the HDD and set a few parameters. Step Two is to actually Format this Partition so it's ready to use for data. After that Windows can actually install itself. If you're starting with a brand new drive the Partition step is simple. About the only details Windows may ask you is how big you want the Primary Partition to be (and by default it probably suggests the entire HDD size) and maybe what File System to use. It will assume you want this to be the Boot Partition and sets it for you without asking.
In your case, watch the messages carefully. Unlike the case of a new drive where there is no choice to make, Windows might actually find that there already are two partitions on the drive (if you did not really delete the Partitions as you think). In that case it may tell you there are two Partitions already and ask which one to use. If you didn't notice this you might just hit a key to accept the default choice and end up with only one Partition prepared and active. But if it does tell you there are two and a choice to make, I would hope it also gives you the option to delete some or all of the existing Partitions so you can start fresh just like a brand new drive. Do it that way and then you should have the option of using the entire 500 GB (it MIGHT be called about 460 GB because of how M$ measures things) to create the Primary Partition and make it your Boot Partition. When it asks you about File system, choose NTFS for such a big drive. Good luck.