The first thing I would try is to disconnect from the internet and temporarily disable my firewall. Run the game, if saves are allowed then you need to make your div.exe a trusted program in your firewall. Your AV program could also be blocking a disk write and may need the div.exe to be added as a trusted program as well..
If I understand correctly you are using the 1.34 version and it will not save. You can play the game but the crash occurs when you try to save. I assume you have lowered all graphics settings on the options page. Upgrading my video drivers eliminated some strange problems I was having with DD when it was first released so I would also recommend doing that.
Click here for ATI Click here for Nvidia Click here for Intel I am running DD on an XP quad core and have RunFirst running when the game launches for the purpose of fixing a sound static problem. If your firewall is not blocking the saves try setting the affinity to a single core and try a save. See
this post for info on how to set the affinity manually. If it helps then I suggest using RunFirst to set it automatically when the game is launched. If setting affinity to a single core manually does not help I wouldn't use RunFirst.
The 1.34 version saves are not compatible with the GOG v1.005A game so loading the 1.34 saves should cause problems if you are using the new version. The V1.005A version has lots of bug fixes and support for higher resolutions. If you can't get the old version to run then getting the newer version from GOG or other distributors may be your best bet for getting the game to run.
Also check out the
DD support page for other info with the reminder that the fixes are suggested for the newer V1.005A release.