Problem with hard drive
I bought this new Western Digital Caviar RE 250GB Serial ATA 150 Hard Drive and now it won't show up in My Computer. I don't know why it won't show up. This is a home built computer. It has Windows XP operating system, an MSI 865PE Neo2 motherboard, 1 Liteon DVD rom drive and 1 CD RW drive, at the moment 2 hard drives, 1 40Gb hard drive and the other a Western Digital 250Gb Serial ATA that I can't seem to use. The hard drive looks as if though it is running but I can't seem to use it. Can anyone help with my dilemma?