Problems that occur as a result of installing Windows XP (and subsequently installing all Windows Updates) on a system that had been working usually are caused by NO DRIVERS or WRONG DRIVERS being installed. Microsoft does not think that searching for proper drivers for your computer's hardware is a Windows XP problem. That is why computer hardware manufacturers (the good ones) post drivers on their website and/or give you a driver CD.
If there is a driver CD that came with the computer, use it to install the proper drivers over the drivers that Windows ''thinks'' should be used.
If no driver CD, then go to Sony.com and download and install the drivers for your particular model. Use the newest driver listed. Follow the installation instructions for the particular driver.
Don't use the drivers that Windows Update suggests for your machine, and don't let Windos automatically choose a driver when clicking the Update Driver button in the properties of a device.
I have a Sony VAIO desktop running Windows XP. I purchased a Comstar 160MB External USB2 Hard-Drive and installed it. Since Windows XP is supposed to have the drivers that are necessary, no driver disk was included, and none was needed.
The problem developed when my Windows XP began to give me problems later. I had to re-install Windows XP. I did that, and I downloaded all Windows XP up dates (including Service Pack 2). Now, this Windows installation does not install the external hard-drive. Windows recognizes that there is "a USB2 device," but Windows states that there are no drivers and asks me to furnish them.
I contacted the Microsoft help desk, but it has been outsourced, and the person responding suggested that I contact Sony for my problem. I reiterated that this was a Windows XP problem, but that hasn't helped.