Not of much help this time round, but for the future seriously consider using a version control system such as Mercurial or Git. Personally I recommend Mercurial as being easier to get up to speed with, especially if you are GUI oriented (see TortoiseHg).
As a bonus places like Bitbucket offer cloud storage for off site repositories and also allows collaboration between developers in small teams.
If you use a revision control system and get into the habit of at least committing before each release or milestone you'll have pretty good confidence that at least you won't lose important code changes.
Premature optimization is the root of all job security