Not sure if it works for all computer makes/models, but this is how I modified my manufacturer link on my Toshiba.
Run regedit.
To modify the text of the manufacturer link in the start menu.. find folder:
HKEY_CLASSES_ROOT\CLSID\{2559a
1f6-21d7-11d4-bdaf
-00c04f60b9f0}
To modify the icon of the manufacturer link.. find folder:
HKEY_CLASSES_ROOT\CLSID\{2559a
1f6-21d7-11d4-bdaf
-00c04f60b9f0}\DefaultIcon
To modify the link ..
HKEY_CLASSES_ROOT\CLSID\{2559a
1f6-21d7-11d4-bdaf-00c04f
60b9f0}\Instance\InitPropertyBag
Hope this helps =)