Cannot find res_dll error

My daughter's Dell Dimension E521 running XP shows Load dll error "Can't load res_dll"  This happened just after removing Linksys software and reinstalling software for a WRT54G.

 

A previous thread mentioned downloading a driver from Linksys for this, but the resolution's success was not documented.  While we'll give that a try this morning, I really would like to know what happened. 

 

Does the Linksys installation remove res_dll?

 

What does res_dll do?  How is the machine impacted by its absence.

 

And, I'll post here how the download from Linksys works. UPDATE:  I have not located on Linksys any reference to res_dll error.  Would appreciate help here more than ever!

 

Thanks!