During the installation you were asked about language, and apparently you accepted the default English.
Excuse me for saying this, but you need to learn about some resources for the future. I am just a newbie, but went to
www.linuxquestions.org, and searched the string "change language mandrake." One of the posts seemed like it might help you--and you should look at all of them if the following does not work. Here is the relevant passage (where German (=de) is the language of choice):
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Open the file /etc/sysconfig/i18n (log on as root, type "gedit" followed by this file name)
This file contains the language instructions for your computer system to use while booting. We will have to append at least the UTF-8 extensions to the ISO annotations of the locales (e.g. for English en_US.UTF-8). As I want my System to work completely in German, my file looks like this:
LC_TELEPHONE=de_DE.UTF-8
LC_CTYPE=de_DE.UTF-8
LANGUAGE=de_DE.UTF-8:de
LC_MONETARY=de_DE.UTF-8
LC_ADDRESS=de_DE.UTF-8
LC_COLLATE=de_DE.UTF-8
LC_NAME=de_DE.UTF-8
LC_PAPER=de_DE.UTF-8
LC_NUMERIC=de_DE.UTF-8
SYSFONT=lat0-16
LC_TIME=de_DE.UTF-8
LC_MEASUREMENT=de_DE.UTF-8
LANG=de_DE.UTF-8
LC_MESSAGES=de_DE.UTF-8
LC_IDENTIFICATION=de_DE.UTF-8
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I assume Spanish would be "SP" instead of "DE"
Somebody who really knows this stuff will hopefully correct me if I am wrong, but this is how I as a newbie would go about trying to solve the problem. Hope this helps.