Missing ODBC Driver

I have a Windows 2000 development server with multiple instance of SQL Server 2000 Dev Edition installed. Recently, i encounter an error on Enterpise Manager.

"A connection could not be established to SERVERNAME\INSTANCENAME.
Reason : Data source name not found and no default driver specified.
Please verify SQL Server is running and check your SQL Server registration properties(by right-clicking on the SERVERNAME\INSTANCENAME node) and try again."

I tried to use Query Analyser on the server to connect to instance. And receive this error

"Unable to connect to server SERVERNAME\INSTANCENAME:
ODBC: Msg 0, Level 16, State 1
[Microsoft][ODBC Driver Manager]Data source name not found and no default driver specified"

I tried connecting using IPAddr\InstanceName and it return the same error.
But if I use another machine (not the Development Server), I can connect to the instance sucessfully using Query Analyser.
Opening up the ODBC Data Source Adminsitrator, under the Drivers tab page, it is empty. So I tried re-installing MDAC 2.8 and also SP1, the installation completed sucessfully but the drivers is still missing. Tried searching on the MSDN site, shows, ODBC Driver cannot be un-installed.
Anybody can help on this ?
Have you changed anyhting on your PC recently? Any updates to the Windows or server? Have you tried to run Component Checker that comes with MDAC to see what could be corrupted in MDAC installation?|||Component Checker reported that I have MDAC 2.8 SP1 ON WINDOWS XP SP2.
But my OS is Windows 2000 SP4|||Does it show any error for the installed drivers/providers?|||I ran the check against the SP and it shows 3 files with mismatch

File : odbcjt32.dll
Mixmatch Fields : Expected : version = 4.0.6304.0
Path : C:\WINNT\system32\
Version : 4.0.6200.0
FileVersion : 4.06200.0
FileDescription : Microsoft ODBC Desktop Driver Pack 3.5
CodePage : 1252
Size : 270608
Date : 06/19/2003

File : msxml3.dll
Mixmatch Fields : Expected : version = 8.50.2162.0
Path : C:\WINNT\system32\
Version : 8.70.1104.0
FileVersion : 8.70.1104.0
FileDescription : MSXML 3.0 SP7
CodePage : 1200
Size : 1049088
Date : 02/18/2005

File : odbcji32.dll
Mixmatch Fields : Expected : version = 4.0.6304.0
Path : C:\WINNT\system32\
Version : 4.0.6200.0
FileVersion : 4.06200.0
FileDescription : Microsoft ODBC Desktop Driver Pack 3.5
CodePage : 1252
Size : 53520
Date : 07/22/2002|||I ran the check against "MDAC 2.8 SP1 ON WINDOWS XP SP2."|||Is the problem i am facing related to SQL Server Data Access or should i post this in Windows 2000 forum instead ?|||It is more related to the Windows installation rather than Data Access to SQL Server. In my opinion MDAC is corrupted somehow|||Thanks for replying.