well, how much RAM do you have in your system?
If it is say 256MB, then add more RAM
A total of 512MB of RAM (2 x 256MB) should be enough, 320MB (256 +
64MB) would be the absolute minimum.
More frugal versions of gOS 3.0 will be released later, see the
"community editions" at the gOS portal, here.
http://gosportal.wordpress.com/communti-editions/
You might try these if for some reason you are unable to add RAM.