Correct me if I'm wrong

(Working with old computer, getting it to work)
I was having problems with re-installing Windows XP and SP1-3 updates, and connecting to internet.and getting DNS errs.
Went into ipconfig, and had no default gateway

So, I eventually found my way to windows error reports,doing a search:
for "setuperr"

Turns out the "computer name" had errors in it with non-allowed characters.
Went into Control Panel, clicked on System, did the fix.
No underlines, etc. allowed

Looking into setuperr logs is really helpful, dont ya think?