Background: I had a clone PC built for me around 1992 by my friend. For it he bought XP Professional. For months it would not work right. I took it back several time, reloaded the O/S several times to no avail. It would reboot and I could not get my applications on it. When Larry finally looked at the Asus manual for it closely, he saw that XP was not specifically identified as being supported by the board. He purchased another board that was designed for XP, installed it and my troubles were over. Current Problem: I am working with an Acer Nobilis Desktop 233 MHz. It is configures with WinXPpro. The mobo will recognize a modem installed on a PCI slot only if forced. That is the Add Hardware wizard is not invoked when the device is installed. In addition, even though I have the driver for it (Motorola MOT PCI3) the O/S will not accept it. I downloaded the mobo manual and found it dated as of July, 1997. The manual also states (I can't copy the PDF text!) ... That it is "PC '97 compliant" ... support plug and play and power management for Win95 and NT. There are no other references to an operating system but it is obvious that the motherboard could not have been designed for any new requirements by XP if it was mfg. in 1997. I suspect that it does not support WinXP. I have not attempted to update the BIOS (Award PnP Extension V1.0A). Can it run XP? Is there updated BIOS that is required? Would I stand a better chance by putting Win98SE or ME on it? My thanks in advance for any advice or comments!