VMware Workstation 4Features | Documentation | Knowledge Base | Discussion Forums
If you are using a virtual machine created under VMware Workstation 3, the first time you power on the virtual machine under VMware Workstation 4, Workstation updates the CMOS. As a result, your guest operating system may detect hardware changes and install new drivers for the new hardware even if you do not choose File > Upgrade Virtual Hardware.
Windows 95 and Windows 98 guests: The first time you run a VMware Workstation 3 virtual machine under VMware Workstation 4, the guest operating system discovers new hardware and attempts to install drivers for it before it loads the CD-ROM driver. As a result, it is unable to load drivers from the operating system installation CD. In many cases, the drivers are already available in C:\Windows, C:\Windows\System or subdirectories under those two directories. However, a simpler approach is to skip any files that Windows does not find at this stage. Then, after the guest operating system has finished loading and is able to read from the CD-ROM, you can run the guest operating system's Add Hardware Wizard and allow it to detect new hardware and install the appropriate drivers.
You need to install the new version of VMware Tools. If you have decided to upgrade the virtual hardware, do that after you finish installing VMware Tools.
Note: If you are upgrading a virtual machine that runs from a physical disk, rather than a virtual disk, you may see the following error message while VMware Workstation is upgrading the virtual hardware: "Unable to upgrade <drivename>. One of the supplied parameters is invalid." You may safely click OK to continue the upgrade process.
If you upgrade the virtual hardware, you may then need to take several steps to be sure the new virtual hardware is recognized properly by the guest operating system. If your guest operating system is listed below, the instructions for that guest operating system provide examples of the steps you may need to take to perform these updates.