I forgot to change the license from trial enterprise to free, as a result caused a few violations.
Is there any way for me to reset the license so that I can resume search?
I'd disagree slightly on the other answer, I would say the easiest approach is to take a backup of your indexes, reinstall Splunk and migrate the indexes back across. This way you will regain your search capabilities immediately.
Read this for details on how to do the backup;
http://docs.splunk.com/Documentation/Splunk/5.0/Indexer/Backupindexeddata
Of course the rest of the answer remains true, don't index so much 🙂
Oranger - this is a well documented subject. Take a look at Kistian Kolb's response here: http://splunk-base.splunk.com/answers/49931/splunk-license-violation