How do you flks dealn with....

the dreaded "Something BAD happened" error?? I'd really like to know.. I just lost four hours of work pushing individual vertices into place by hand because of this and i just dont know what to do about it.. Is there an autosave someplace i can turn on to keep this from happening?? I'm just terribly sick of losing work like that..
Thanks
Pam
Thanks
Pam