Look in the game settings and see if there's a setting for Hardware Mode vs Software Mode. If you're set to Hardware Mode, try Software Mode.
The Web Archive link for Dreamcatcher's old support page is
***here***. They suggest Software Mode for low end computers on the page, but Software Mode also tends to be more stable because it doesn't depend so much on your video card drivers.
If you haven't installed the patch, you might try that (unless you're using a pre-patched version of the game). Here's the description:
# The Omega Stone v1.10 Patch (3.4 MB)
The following issues have been fixed for version 1.10:
-Crashing to Desktop for Windows 2000 Users.
-Fix beeping at StoneHenge which stays with player.
-The Celtic Altar skulls visual bug is corrected.
-All areas with no music now fixed. -Multiple snake skulls can no longer be acquired.
-Magnifying glass appeared even after objects have been picked up.
-Chichen Itza stone slab clue for skull puzzle now more lit up.
-Fixed sounds when picking up Jade Mask at Chichen Itza.
-a few other minor sound and graphical glitches corrected.
Since this is an old patch, the "Crashing to Desktop for Windows 2000 Users" would probably include any NT-based version of Windows later than Windows 2000, though the description hasn't been updated to reflect this.