Virtual machines run very slowly in Virtual PC 2004 or in Virtual Server 2005

After you configure a virtual machine in Microsoft Virtual Server 2005 or in Microsoft Virtual PC 2004, that virtual machine runs very slowly.

This issue occurs although you have configured the performance options for that virtual machine and although you have installed Virtual Machine Additions on that virtual machine.

This issue may occur if you have the Computer Associates eTrust Antivirus 7.0 program installed on the host computer.

This issue occurs if the eTrust Antivirus Realtime Monitor component monitors the Virtual Server or Virtual PC service. This issue also occurs if the eTrust Antivirus Realtime Monitor component monitors the Virtual Server or Virtual PC files.

To resolve this issue, configure the eTrust Antivirus Realtime Monitor settings to exclude the following processes:

• For Virtual Server 2005, exclude the Vssrvc.exe process
• For Virtual PC 2004, exclude the Virtual PC.exe process

To do this, follow these steps:

1. In the notification area of the host computer, right-click the eTrust Antivirus icon, and then click Realtime Options.
2. Click the Filters tab, and the click Process.
3. In the Enter a process name box, type the name of the process that you want to exclude, and then click Add.
4. Click OK two times.

Additionally, configure the eTrust Antivirus Realtime Monitor to exclude the following file name extensions:

• .vhd
• .vmc
• .vsv
• .vud
• .vfd
• .iso

To do this, follow these steps:

1. In the notification area of the host computer, right-click the eTrust Antivirus icon, and then click Realtime Options.
2. Click the Selection tab, and then click Edit List.
3. In the Enter a New File Extension here box, type the name of the file name extension that you want to exclude, and then click Add. For example, type vhd, and then click Add.
4. After you have finished adding file name extensions to the exclusion list, click OK two times.

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.