I assume that you're using the latest version of ArtRage, which should be the case if you purchased from us. It's 2.5.20 and you can check by going to Help -> About ArtRage and checking the version there.
If not, you can download the latest from www.artrage.com/artrageinstaller.html
Do you get the crash when you click on any tool, or is it a specific tool? If so, which one?
Are you using a mouse or do you also have a tablet or other input device? If so, what make and model is it?
If there is an error message, what is the exact text, as this may help in understanding the problem.
You can also email me directly at email@example.com directly for support with this and I'll be happy to troubleshoot the problem with you.