When I try to search something on my web and I write only three or four characters on the search field, it doesn't show the search results but shows this: "Keywords must be at least 5 characters long" and "Keywords shorter than 5 characters will be ignored"...

So I cannot search through the web if I don't write 5 characters.
Is there anyway to change this. Ex. to make the minimun keywords 2 or 3. Or to delete it all and make no min.keywords needed.

Thanks in advance

When you install any CMS, there are some settings to set and make it work the way you wish.
In your admin section of any site or this site, there is a 'CONFIGURATION' system hidden somewhere, - with that you will dictate to your site the way it should work.

Log in to your website as admin go to admin click on system admin preferences then click on search and set the minimum keyword length to 2 or 3 charachters and submit - that should fix it.