If your sound card is that old that could be your issue.
You can get new sound cards for just over £30 from places like
www.scan.co.uk.
It might be time for you to upgrade it. Plus the Celeron CPU is going to struggle with this game. I run a 733Mhv PIII and when there are lots of planes on the screen things slow down for me too.
There are some VERY good upgrade deals out there at the moment. Maybe it's time to get that 1GHz machine you always dream about ! ( and that is the lowest CPU you can get hold of today ! The 2GHz machine is out now )
Have a look at
http://www.misco.co.uk/systems/defau...GA351N855073GF
You could upgrade your box for as little as £450.
Bingo
