Hi Carina
I've had a similar problem. I could run the non R algorithms, but when running R PA would start and then crash just as you have described. I solved the issue by:
1. Edited the PC registry by searching for R-3 and deleting all keys etc that related to R.
2. Remove all environmental variables that referenced R such as the path variable.
3. Deleted all R content from my all my hard drives.
4. Re-booted my PC.
5. Installed and configured R via Predictive Analysis.
I was able to run R algorithms after this.
Hope this helps
Jon