when i planned to install ubuntu, i found amd image. even though my system is intel based i stared my installation with the AMD image and installation went through. Now im facing many issues because of this.. is there a way i can change main things which impact this (like kernel headers etc)

I don't think it would be easy to do. It is best to start with an image designed for the chipset you have.

By the way i386 = 32 bit - Many systems these days are 64 bit so you might want to get an x86_64 image rather than i386.
Also note that there are packages on 32 bit systems called i586 and i686 - not generally a problem.

You can freely download and burn your own Linux CD/DVD from any places. If you don't have access to a burner you might want to find your local Linux Users Group (LUG). Usually people at a LUG are more than willing to provide you a copy of Linux and may even help you do the install.

If you have installed the amd64 image this means nothing more than that you have installed the 64 bit version of Ubuntu. Despite of its name that image is appropriate for all x86_84 CPUs, including the ones from Intel and VIA. It is just named after AMD because they have invented the 64 bit extensions for x86 CPUs.
The i386 image just denotes the 32 bit version (and despite its name it will not run on i386 CPUs) of Ubuntu.

To your problem: While it is possible to run a 64 bit kernel with a 32 bit userland it is not possible to do it the other way around. The 64 bit userland will not run on a 32 bit kernel. So if you really want to use the 32 bit version you have to do a complete re-install with that version.

But may be it is possible that we can help you to solve your problems with the 64 bit version, just open a new thread that includes the following info:
- Distribution (in your case Ubuntu) and version of the distribution
- If your problems are hardware related of course the hardware specifications of your machine
- An exact description of your problems, including exact error messages you get under which circumstances.

thanks for the reply

I am confident you have mis diagnosed your problems. You are blaming problems on your choice of AMD64 architecture without any evidence that the choice of architecture affects those issues at all.

Describe specific issues you are having and you will very likely get good instructions on how to resolve those issues and very likely none of that will require changing to 32 bit Linux.

In the unlikely event that you are correct and the choice of AMD64 is causing problems, then TobiSGD is correct: You cannot switch to i386 without a complete reinstall of Linux.