Yes, I also have SU 6 installed (and separately licensed). Then I also have SU 7.0 and 7.1 separately installed, too (although their licensing is not separate). So you can have a whole bunch of versions installed separately and you can even run them together if you wish. Note that if you double click on an skp file (and launch SU this way) it will always try to launch the version you saved anything in last. Also note that while you can open SU 6 files in SU 7 (and even "save as..." a v.6 file), you cannot open a v.7 file in SU 6. I think that's all.

lemastre, I dont know shat version you are working with, but the software is definatly more powerful than the price! The possibilities with SU are there, you just have to quit thinking your working with cad. Hang out around here, check out back-to-school tutorials, the standard SU tuts, and there was a guy around named diedre bur (sorry about messing up the name) who had some very good plan drawing tutorials that will get you started quick. I think he is found on the Spirit Cad site. If that doesn't work I can get you a contact. good luck.