Before installing V 4.2, I have some questions. 

• Does installing V 4.2 replace V4 and V4.1.  I sure want to try it, but not risk replacing characters that work with something that has problems, and then find it cannot be un-installed or the old characters cannot be recovered.

• If it does overwrite, can the main runtime be backed up and then restored to recover the V4 and V4.1 if needed?

• Do V4 and V4.1 (if there are any) clothing and items fit V4.2?

Any help is appreciated. 

Just copy your runtime to another folder then install v4.2 as if somit goes wrong can put runtime back over, i just copy runtime over then rename v4.0 or 4.1 depending what v4 you got.
I found that when  installed 4.2 on computer without Internet connection could not get her work.
Had install on comp with open internet then transfer other comp, though will say never update the v4 as if i want use 3 v4s in a scene, i use v4.0 as less memory then v4.1 bit more memory then v2 with every thing loaded and much more memory.
Just copy ya runtime so if goes screwy  just copy back over.

After reading comments in other forums posts here and elsewhere I'm holding off installing for the moment, seems to be too many problems for a lot of peeps for me to risk it!

I've found that V4.2 can be run from an external runtime but you have to copy the !Daz folder to your main runtime to get the morphs working, apart from that I've had no problems.

I have the same impression as the person who said hold off.  The install process seems too complex, and there's too much that can go wrong.

Quote - The install process seems too complex, and there's too much that can go wrong.

It's not complex at all, but it will install on top of V4.1.

If you want to keep your existing V4.1, just to be on the safe side, that's where it could get complicated. If you're used to moving Runtimes around, or moving files between Runtimes, you should be able to figure out a way that suits you.

If you have the Creature morphs package installed , you have to uninstall V4.1, and that is where it gets fiddly. As far as I can see, this is the only bit that can 'go wrong'.

DAZ deserve to get flak for this and the huge cockup they made with the early release, which may be where the over-the-top paranoia with which this release is regarded has come from.