After doing lots of troubleshooting to install ODBC drivers on windows 2003 OS machine, I found that it was 64 bit where I was trying to
install 32 bit ODBC Drivers.
  well, here is command to know what type of CPU architecture you have.
Open a command prompt and execute systeminfo.exe

C:\>systeminfo.exe

Host Name:                 xxx
OS Name:                   Microsoft Windows XP Professional
OS Version:                5.1.2600 Service Pack 3 Build 2600
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Member Workstation
OS Build Type:             Multiprocessor Free
Registered Owner:         
Registered Organization:  
Product ID:               
Original Install Date:     11/16/2005, 3:10:01 PM
System Up Time:            0 Days, 3 Hours, 39 Minutes, 28 Seconds
System Manufacturer:       Gigabyte Technology Co., Ltd.
System Model:              945GCMX-S2
System type:               X86-based PC
Processor(s):              1 Processor(s) Installed.

Below are the results for 64 bit machine

C:\Documents and Settings\Administrator>systeminfo.exe

Host Name:                 xxxx-xxxx
OS Name:                   Microsoft(R) Windows(R) Server 2003 Enterprise x64 E
ition
OS Version:                5.2.3790 Service Pack 2 Build 3790
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Standalone Server
OS Build Type:             Multiprocessor Free
Registered Owner:          xxx
Registered Organization:   xxx
Product ID:                
Original Install Date:     4/3/2008, 6:39:26 AM
System Up Time:            0 Days, 3 Hours, 29 Minutes, 11 Seconds
System Manufacturer:       
System Model:              AWRDACPI
System Type:               x64-based PC
Processor(s):              2 Processor(s) Installed.

Systeminfo.exe is very useful command to know your PC configuration and Service pack info etc.

Before downloading any software make sure that you are downloading correct version or edition which supports your CPU architecture.

Satalaj