I currently have a Seagate Barracuda 7200.11 500 MB Hard Drive on my Dell 9200 Series XPS 410. I ordered a Seagate Barracuda 7200.11 1.5TB Hard Drive:

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=4138129&SRCCODE=WEBLET03ORDER&cm_mmc=Email-_-WebletMain-_-WEBLET03ORDER-_-Deals

A Ultra SATA II 3Gbps Cable w/4-Pin Molex to 15-Pin Power Adapter Cable:

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=3264908&SRCCODE=WEBLET03ORDER&cm_mmc=Email-_-WebletMain-_-WEBLET03ORDER-_-Deals

And a Hard Drive Screws - 5-Pack:

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=5086211&SRCCODE=WEBLET03ORDER&cm_mmc=Email-_-WebletMain-_-WEBLET03ORDER-_-Deals

Is this everything I need to install it in my Dell?

Will installing a much larger hard drive cause my computer to slow down? The folks at Tiger Direct tried to sell me some software and justified it with a bunch of BS saying it would make the computer and the drive much faster. My BS detector was going off so I passed on the sales pitch.

What is my next step. I want to install this larger hard drive, copy the current 500MB hard drive to it and make it the primary hard drive and the 500 MB drive the secondary drive. TIA.

That should be everything you need although I don't think you need the screws because my Dad has a Dell XPS 410 system and the hard drive mounting is completely screw-less in it. Speed wise there shouldn't be any noticeable difference between the new and old drive. As for copying the old drive onto the new one I'm not too sure how one would go about doing that.

As fr the copying of the hard drive I normally use Nortn's Ghost which was actually PowerQuest Drive Image years ago. But regardless the Norton Ghost 14 or 15 will make a prefect copy of the orignal drive and place it on the new drive. Comes with its own boot disk and operating system. After that its works flawless as a backup program... As for larger drives you will see a slow down after they load up with information say 1 TB or so... The way the hard drive works is that windows asks for a file the hard drive must go the index and look up the placement of the file on the drive. Then go read the file from the drive. Kind of like having encyclopedias and using the index book to look up "diesel" and pull the book and look up the pages. Now what I've normally always done to gain just a small bit of performance back is to partition the dirve up. So using your 1.5 TB drive I would consider doing 250 GB partitions or 500 GB partitions. So now your index table is greatly shorten. If a logicall drive error occurs it only effects the logical drive not he entire drive. Or better yet if a virus land on the drive it only a small drive to scan much faster. As for the screws I'm got close to 50# of those... I'll give them to you if needed...