Does anybody know how to delete "locked" network settings pre-installed by service provider?

I've tried the following steps but doesn't seem to work:
1) Hard reset - this deletes everything, network settings blank.
2) Delete all network files (.prprpr*) $files$ $in$ $the$ /$backup$ $directory$.
3) Hotsync, to restore my data.
It just created new network .prprpr* $files$.