That model computer cannot use hard disks over 120GB. You have to get a smaller hard drive. It sounds like you cloned the old 60gb drive and put it on the new drive. It might work for a short time, but sooner or later the disk will fail. It will also be unreliable because of the size limits of the I6000. You need to install windows on a new smaller drive. 

I cloned nothing.  The 120 GB Seagate drive died, and I wanted to replace it with a 250 GB EIDE drive.  Why would a 120 GB drive restriction apply?  Your response seems invalid since Dell offers a 320GB drive for my Inspiron 6000.

The BIOS of the I-6000 predates the larger drives; it contains an algorithm for addressing hard drive sectors that results in a limit of about 137 GB.  Since Windows uses its own hard drive algorithms this is not an absolute limit.  Provided you're using a Windows XP installation CD that incorporates Service Pack 1 or later it is possible to format your hard drive as a single partition, and it should work for at least a while.

The problem that can result, a crash of the hard drive, is the result of the way the system begins the boot process.  The BIOS code reads the initial boot code into memory which requires the use of the BIOS hard drive algorithm.  If the system produces an error in the sector address that causes that address to be beyond the limit, the system wraps around and begins counting again from zero.  This will wipe out your boot drive and if using a single partition, your data along with it.

For safety it is usually recommended that you partition the hard drive into two partitions, the first being smaller than the limit (80 GB to 120 GB) and used as the boot drive.  Your Windows OS and your applications would be installed there.  Once you have Windows installed you can use the Disk Management application to partition and format the second partition on the drive for your data.  Having the first partition smaller than the BIOS limit helps to prevent a crash in the first place, and if a crash happens anyway, you can reinstall Windows and your applications into that partition without disturbing the data you have on the second partition.

With regard to your second question, did you install the device drivers when you loaded Windows?  If not, you need to install the drivers as follows:  Notebook System Software, Intel Chipset driver, followed by the drivers for your remaining devices.  Dell suggests that you install the drivers for your display, network (Ethernet), and sound after the first two I mentioned but before anything else to minimize resource problems.

Thank you.  Obviously, you and Mary know a lot more about the limits and restrictions on my computer than I, and I really appreciate your explanation.  It does loook as though my accidental creation of the 50 GB partition was aa good thing.  I'd like to make it about 100 GB, but am unsure of the steps.  Dell's suppport certainly must set forth the instructions for reinstallation of drivers, etc. I did place the Dell-provided drivers CD in the DVD slot, but obviously did not properly install the drivers.  When you don't know what you're doing, nothing is as simple as it should be.

Somedays nothing is as easy as it should be.  I haven't seen the Resource CD for the I-6000, but I know the one for the Dimension 2400 requires you to click on each driver having a check-mark to the left and open the file in order to begin the self-extractor.  Once that has completed you should get a prompt to close the self-extractor, and after you do that, an installation wizard should appear.  Regrettably this must be done one driver at a time with a restart of the computer between each file so that the Windows registry will be updated before you install the next file.

With regard to your partition, Windows setup has a screen that allows you to delete and create partitions.  If you have nothing installed other than Windows it is probably easiest to boot to the installation CD once more, delete the partition you have, and create one of the size you prefer.  I believe you can also use something like Partition Magic to expand the partition you already have into the unallocated space, but that requires you either purchase or download another application.