Can Daz 4.8 be installed in a way as not to interfere with 4.7?
When I installed Daz 4.7 Beta, it overwrote my Daz 4.5, so when I click on the 4.5 icon on my desktop, Daz 4.7 loads.
I want to try 4.8, but am unsure about system compatibility, as I have some doubt it will work with my graphics card. I just don't want to get into a mess trying to uninstall 4.8 and losing my 4.7 work.

Comments
I have both 4.7 and 4.8 on the same PC with no problems.
You have to use DIM (DAZ Install Manager) to download and install 4.8, that way, both version stay on the same machine. Installing or uninstalling DS should not affect content in any way.
4.7 is not a beta it is the latest stable release so of course it overwrote the old stable release in 4.x range. 4.8 is a public beta and must be installed by DIM so that it doesn't accidentally overwrite your stable version.
Is this overwriting a Windows thing? On my Mac, I have three versions of DAZ Studio... 2.something, 4.5 and 4.6...
On my Windows laptop I only have 4.7 and I never bothered to try installing another version at the same time.
I'm curious because I was considering installing 3 Pro on it.
I have 2.0 and 3.1 installed, along with two versions each of 4.0, 4.5, 4.6, and 4.7 (x32 and x64 of each, respectively), along with "4-8 x64 PB" (PB for Public Beta). I rarely open more than two versions at a time, and have not had any difficulty.
It isn't advisable to have more that one release version of DS4+ installed, although you can have both release and public beta, and you can have both 32-bit and 64-bit installed. Similarly you can have one DS3 (32 & 64 bit) installed and one DS2 installed. DS2, 3, and 4 don't interfere with each other.
When I installed 4.8, I didn't do anything special through DIM.
It created a separate folder for 4.8 Public Build, and it didn't touch my 4.7 folder.
I had to navigate to the new folder to open 4.8 (since 4.7 sits on my Taskbar, and I'm used to clicking on the Taskbar in Win7).
Windows changed almost everything on my pc yesterday. I didn't ask for the change it just did it. Now my Daz icon is gone from the desktop. I don't know how to get it back. I found my Daz stuff so at least it's still there. I can open a scene but it launches another program of Daz with nothing in it. No smart content and nothing in my render library. I don't know what to do to get everything back the way it was. I'm a newbie and I will greatly appreciate any and all help. Thank you all very much
Once you find the Studio launch icon right-click on and select Send to... Desktop (create shortcut).
There should be a lnk in Start Menu > Programs > DAZ 3D > DAZ Studio 4
Does your content how in Content Library > Daz Studio Formats and Content Library > Poser Formats? If it does try Content DB Maintenance > Re-Import Metadata.