AutoCad-computer locks up

For some reason, each time I open AutoCad my computer locks up. It just recently went into a memory scan and said it could not find an operating system. I have had this program installed over a year and have never had this problem. I have not installed any new programs of note (Google chrome), and I constantly run and clean the programs listed to keep my pc free of malware/spyware, etc. I have a Dell laptop running Vista business. I do not have the original version of AutoCad so uninstall/reinstall is not a good option. Any advice???

 

have you updated your video drivers recently? (either manually or through windows update)

 

Not to my knowledge. Unless it happens automatically I would say no. I made another post with log files attached if that helps...