This is unlikely to be an error with Construct 2 as thousands of people are successfully using it.
It is much more likely to be an issue with your computer, but as you have provided virtually no information, there is probably nothing anyone can do to help you.
What OS? GPU? Memory?
Have you tried a clean install of the latest beta?
Try uninstalling the current version, reboot, install r169 (link at bottom of page)..
Also make sure your graphic driver is up to date.