The first thing that I will recommend is that you go and explain to your boss what has happened. Hiding mistakes makes them worse, and there's a good chance that you will not be able to get the data back.
What recovery model is the database in? I assume, with no backups of any form, it's in simple recovery.
How long ago were the rows deleted?
You can try RedGate's log explorer (as Ninja suggested) or one of the other log recovery tools. I don't know which ones can read SQL 7. If the DB is in simple recovery, then it's quite likely that the log records for the delete have been discarded already. You can give it a try, but no promises.
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
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