my laptop running windows xp does not recognize WD external mass storage device. In the past it did recognize. Sometimes it will recognize, but only after the computer has been on for a long time, an hour or even longer. What can I do?
Give us a little more information to go on. Need to know if your Win XP is running SP-3, and if all the updates are installed. Next what is the model # and size of the WD external HDD, is it connected by a USB cord or other connection, USB2 or USB3, and if it has an external power supply or get it's power from the USB connection.
Just from the little info available, could be the ext drive is only getting marginal power from the laptop, and an extrnal power source should be tried if that's part of the package.
Well, think we should take this in a systemic step wise fashion, since intermittant problems are much tougher to diagnose than constant ones.
Do a couple easy things first. Change the USB connector cable, and plug the USB laptop end into a different connector to see it that helps. If not make usre when the ext drive isn't recognized that the green light on the power block is on at all times and the drive can be heard spinning. The power block can be a common problem so spend a little time checking the power supply to make sure it is delivering power to the ext drive when it is both not recognized and recognized.
Next, when it is powered up and not recognized, boot into the StartUp screen and in the BIOS make sure the WD HDD is listed with model # just below the fixed laptop drive..
Then boot up to the desktop, go to the Device manager, and check in the HDD section that it is listed. Double click on the entry and it should say "this device is working properly". When recognzed, do the same thing.
Lastly, go to Disk Management, right click My Computer, Manage, Computer Management, and in the lower left click on Disk Management. In the lower graphical area, see if this drive is recognized. (probably Drive 1 or Drive 2, and report what is says under the Drive column and the Volume column just to the right.
If you can do that both when it isn't recognized and when recognized, that should give us the info needed to pin down the problem.