Second Drive question

Your problem is with the WD 640 GB unit, right? It looks to me as if you have not done the two steps necessary to get a drive running under Windows. First is Partition (creates the Partition Table on the drive defining exactly how many Partitions there are on it, their sizes, and where they start, and sets up the first Partition). You may want to make only one Partition that takes up all the space on this drive. Second is Format (done separately for each Partition), which establishes on each Partition the Root Directory and all the hidden data tables necessary to keep track of the use of sectors on the drive. After both these are done, Windows can find and use them.

You can do these yourself in the Disk Manager. Click on Start, then RIGHT-click on My Computer, then choose Manage from the menu. In the resulting Computer Management window's left pane, expand Storage if necessary and click on Disk Management. In the right upper pane you'll see the drives you can see and use. In the right LOWER pane you'll see those plus some other drives that can't be used yet. RIGHT-click on your 640GB drive and use the menus to choose the Partitioning tool. Come back to this for the Format tool. When done you reboot and see if the drive now shows up in My Computer.

Even easier, do you have the WD Data Lifeguard tools (free on their website). Since you have two other WD drives installed, maybe you have these software tools, too. That tool kit includes all the things you need to set up your new empty drive and get it ready for Windows to use. Then you don't have to navigate through the DIY tools in Disk Manager.

Thank you very much...Formatting as we speak!

I had not installed an internal HD in years but am in the proces of isntalling a 1T WD Caviar Drive into an older Gateway model and what shoudl have taken 10 minutes has no taken over 2 hours.. happenned to come across this advice and thanx its formattign now .. The Lifeguard tools failed to run at all so hopefully this looks liek thigns ae on the right track.
Would have been nice if WD isntallation manual told us to change the bios settings from RAID to IDE and also set this procedure for us in the manuals.....

Thanks RJM