运行ANSYS8.0出错，大家看看这个问题怎么解决？

求助！我运行软件程序时提示出现下面错误，该怎么解决？
  
***FATAL****
The database <-db> space requested is not currently available.
Reenter ANSYS command line with less database space requested.
*******
The above error is non-recoverable by ANSYS
ANSYS run terminated by the indicated error
Current data base saved if possible.
  
上面的文字是dos下显示的，摘了部分。