When I open ilustrator with blank art board it wont let me draw every tool has little X in lower right of the tool....How to start drawing free hand?.....
It sounds as if someone has given you a UPTF version (Use Pen Tool First).
Or, you may try the following (you may have tried/done some of them already) and see whether it helps:
1) Close down Illy and open again;
2) Restart the computer;
3) Close down Illy and press Ctrl+Alt+Shift/Cmd+Option+Shift during startup (irreversible);
4) Move the folder with Illy closed (reversible);
5) Look through and try out the relevant among the Other options;
Even more seriously, you may:
6) Uninstall, run the Cleaner Tool if you have CS3/CS4/CS5/CS6, and reinstall.