Because Windows95,Windows 95A, and Windows 95B can't detect Intel 440BX chip, it causes system to appear question mark "PCI card","PCI bridge". This utility will fix these problems and only use for ASUSTeK's motherboard. Install: Run PX4PATCH.EXE to install. Uninstall: Run PX4PATCH.EXE again and select uninstall item. PS: In Windows 95B version if you want to use USB device that you need to install USBSUPP program and this program you can get it from Microsoft.