What do you mean by "crashing"?
Do you get an error message that "Lightroom has stopped working"? In this case you have a crash and probably should re-install Lr.
Or does Lr just become unresponsive? In this case wait a while until Lr becomes responsive again. "Just clicking a raound" can actually cause that your systems resources to max out because with each click Lr will have to do something, and will be unresponsive for a while until it has caught up with your clicks.
Naturally, it depends a lot on your system.
Here are the system requirements for Windows:
System requirements
Windows
- Intel® Pentium® 4 or AMD Athlon® 64 processor
- Microsoft® Windows Vista or Windows 7 with Service Pack 1 or Windows 8
- 2GB of RAM
- 1GB of available hard-disk space
- 1024x768 display
- DVD-ROM drive (if installing from DVD)
- Internet connection required for Internet-based services*
