With this being your wife's computer and the fact that you have physical access to it, as a last resort if you can't reset the password so you can gain access you could remove the hard drive from her computer and connect it to another. Once you boot the computer you would just copy the contents over from one hard drive to another and then format, reload and then copy the backed up data over to her computer again. If this is a laptop you would need a device to connect the hard drive to another system but this would be no problem with a PC. Before you go that route though what OS is your wife's computer running? Once that is answered I will have more suggestions to try.
A+, Security+, MCP, MCSA:Security - Server 2003, MCSE:Security - Server 2003, MCTS, MCITP: Enterprise Support Technician, MCITP: Server Administrator
Presently working on C|EH