How do i reprogram a Hitachi 60" remote

Check all the input connections for firmness. Especially to its Ariel connection. If all is found OK, check and replace the tuner. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/

If you wish to buy its original remote control, contact the authorized service centre, or authorized dealer to your device brand. They can either give you a genuine remote control to your device, or can direct you, from where can you purchase a suitable one.
To select a proper universal remote control, you should know about the number of digits to its set-up codes. There are 3 digit, 4 digit, 5 digit, 2 digit and even single digit codes, to some brand devices. After confirming this, check the sites linked here. Both the sites have set-up code list and set-up procedure to many popular brand remote controls. Check which brand remote control has set-up code/s to your device brand, and buy that one according to availability.
Brand name of the remote control isn't a matter, but it should have set-up codes in its code list, to the device brand you have.
Please note: Every new universal remote control will have set-up code list, and set-up procedure along with its pack. Never accept a remote control, that hasn't both of this. For more details about the set-up codes, visit the site http://electrohelponline.blogspot.com/ Check this site too. http://remotesearch.blogspot.com/ Universal remote controls are available at most of the electronic spare part selling shops.

Refer its user manual for details.

Here is a link to the manual with component codes for this remote:
http://remotes.com/remotes/documents/Hitachi/CLU-5729TSI.pdf

CONTACT HITACHI TECH SUPPORT

Tries this website for a new remote 1-800-Remotes Factory original for new remote or tries the manual controls on the tv for functions to ajust the screeen sizes.

I have Hitachi universal remote CLU - 5729TSI how can I Program it to change the code for a different tv. a toshiba 36 inch it is around a 1999-2000 model.

I solved it myself. I actually found the manuals for both the tv that the Hitachi remote came with and for our LG.  The codes for programing the tv the remote came with were all two digit, like 24, 01, 34, etc.  All the codes for the LG are three digit codes, 001, 210, etc.  So I am pretty sure they will not speak to each other.  The Hitachi is just a bit too outdated.

You can get a replacement from the links below:

Hitachi TV Remote Control HITACHI CLU-4362S remote control CLU4362S


Hitachi CLU-4362S Projection TV Remote Control


Hitachi CLU-4362S Projection TV Remote Control ~ - eBay


Hitachi CLU4362S Replacement Remote Contro

If you provide model number I can suggest correct remote control to buy.