Apparently.
I'm very surprised that the Ethernet cable doesn't work since that rarely requires a driver just to work.
1) Go to a working PC
2) Dell support site, then type in dell number on laptop which takes you to proper support site for your model
3) Download the wireless drivers to a USB stick
4) Insert USB stick into laptop and install wireless drivers
5) Setup wireless for your laptop
6) Once working, go back to Dell site and download/install the main "Dell Support Center" software or whatever it's called. This program should handle driver installation automatically. If not do it manually (including latest video drivers from Dell site).
Other:
I'm not quite sure HOW you did a clean install since restoring the factory backup Image (started with one of the F-Keys on startup) would simply default to the exact state it was when you bought it which would have working wireless.
If you installed via a generic OEM Vista Install disc (not one for your laptop specifically) then you can likely use video drivers from Intel/AMD/NVidia direct as appropriate otherwise usually you need to use the ones for your EXACT model from the support site (Laptop manufacturers modify the Windows code to prevent video drivers they didn't modify from installing since they often add links to keyboard buttons. Unfortunately they don't keep updating the drivers)
*If you updated to W7 or W8 instead which you don't state but I don't want to assume it's Vista then it's possible you may have issues with drivers though I didn't myself. I'm not sure if the Dell Support Center software would work or not in this case, though personally I did NOT have to install any drivers anyway going to W8 except for the media card unit and then I just used the Vista ones and they did work.