Yes but you'll need to unregister the dlls BEFORE you delete them because it needs the actual file otherwise you'll have to run RegClean (do a search for this on the Microsoft website) or just go through the registry and delete the entries that you don't need anymore. To unregister a dll you use the same method as registering it only with a /u switch added, like this:

regsvr32 "C:\Program Files\Microsoft Visual Studio\VB98\Temp\dllExample\dllExample.dll" /u <-just add the /u to the end to unregister.