There are many reasons why a PC might crash ranging from running out of disk space through failing components (RAM, hard disk) to a virus infection. It's best to follow the PC manufacturer's diagnostic advice.

However, that PC does have a good record of completing CPDN HADAM3P regional models. It does not have a good success rate with the longer HADCM3N models.

If you want to improve the success rate with CPDN models then it would be a good idea to restrict the model types being run to just HADAM3P. To do this, select 'Your account' in the menu on the left-hand side of the browser window and follow the link 'climateprediction.net preferences'.

If you think that running CPDN models might be causing the PC crashes, then you could try restricting the number of models to just one at a time. Follow the 'Computing preferences' link in 'Your account' and change the 'On multiprocessors, use at most' setting to 50% or even 25%: that will change the setting for all your computers. If you want to change the setting for only that PC then there is an equivalent setting in BOINC Manager, accessed via 'Tools | Computing preferences | processor usage' (in the English version).