client won't start with backup wallet file.

[nazgulnarsil]

tried deleting everything in bitcoin folder except wallet file.  bitcoin refuses to run and states:
11Dbexception
Db::open:invalid argument

and closes immediately.

completely lost on how to use bitcoin tools.  downloaded python and bitcoin tools but get errors when I try to run any bitcoin tools commands. (windows 7)

halp there are 7 coins in this wallet. 

[Maged]

Be sure to use the Python 2.x branch, not 3.x.

[nazgulnarsil]

thanks.  how do I install the required python crypto library?

without it installed I get "error couldn't open wallet.dat/main"