We're getting ready to upgrade our Windows NT domain, which contains two NT 4.0 domain controllers (DCs), to Windows 2000, and we're going to implement Active Directory (AD). We use a mix of Windows clients running everything from Windows XP to Windows 98 Second Edition (Win98SE). The name of our NT domain includes an underscore (_). Will this character cause any problems when we upgrade?

No. You can configure the Win2K DNS server to allow or disallow the use of UTF-8 characters, such as the underscore. Open the Microsoft Management Console (MMC) DNS snap-in. Select the Win2K DNS server and open its Properties dialog box. Go to the Advanced tab and select Non RFC (ANSI) from the Name checking drop-down list. Select Non RFC (ANSI) to permit the use of the underscore in a name.