The default is C: that is the default drive letter, the default drive number is Disk 0
Windows Server Backup utility
To function as a server a computer must be running as a WINDOWS based server i.e windows 2000, windows NT, windows 2k3, windows 2k8 editions of server installed on computer the server could be Linux based as well.
remote desktop client
File services
I assume you mean the OS on the server, if you want to go with windows your looking at windows server 2003 / 2008, windows small business server, windows home server. However alot of admins prefer linux, try FreeBSD.
.NET Framework is part of the Operating System rather than the hardware. It can be installed on Windows based systems..NET 1.1 comes preinstalled in Windows Server 2003, .NET 3.0 in Windows Vista and Windows Server 2008, .NET 3.5 in Windows 7 and Windows Server 2008 R2.
Yes, there is no problem installing that version of .NET on the server.
Print Services
You'll need to edit boot.ini and add an entry for Windows XP.
servermanagercmd.exe -showroles
port
port