The first thing to try is a Safe Boot, To do this can you shut the machine down then wait 5 seconds and power it back up.
As soon as you let go of the power button can you press and hold down the SHIFT key and keep it pressed till the machine shows the load wheel below the Apple icon then let go and wait up to 30 minutes for the machine to open to the Safe Boot login.
When the login screen comes up can you then try to login to your Wifes user account and then see if it will open or not.
If it will can you then restart just like normal from the Apple menu and once your machine has rebooted can you then try and login to your Wifes account in the full mode of OSX and let me know what happens or at what point you had an issue.
So it bluescreened in Safe Boot, correct?
If so can you boot the Mac like normal and then login as yourself and then can you do a spotlight search for the ApplicationEnhancer.bundle and when you find it can you move the file to the trash then restart and see if you can then login to your wifes account.
If not can you tell me if there is anything at all on the blue screen?
Can you tell me how much information is stored on your wifes user account?
Do you know where her info is stored, such as documents, music, email?
The reason I ask is I would like to try the path of least resistance which would be to create a new user account then transfer her files, etc. into the new user's folders from the finder then see if you can login as the new user and access her files cleanly.
Let me know
From your account can you open teh Mac Hdd and then go to Applications, Utilities and open the Directory Utility then type your password XXXXX authenticate and then go to edit and select Enable Root User and type in your choice of Root password.
Once you have your root user set up can you then sign out of the current account by clicking the top left apple menu and selecting Log Out then once you are at the log in screen can you select Other from the list of users and then type Root for the username and enter the password XXXXX just set up.Once you are logged into the root account can you then click on Finder and go to your Mac HDD and all your accounts should be in the Users directory so you can select your Wife's account and see if you can then see them so you can then move them and let me know what happens
Sorry I just remembered you are using Tiger so that was my mistake.
You will need to use the Netinfo utility from the utilities folder, So can you open it up then can you follow the steps in this Apple document to setup the root access http://support.apple.com/kb/HT1528
Once you are done let me know if you have any issues
If you have your OSX disks you can perform what is known as an Archive and install, This is where you can reinstall the OS but keep all of your files in anarchive folder so you can then restore them after the reload.
If you would like instructions I would be more than happy to give them to you or if you prefer the Apple store will be able to do this for you with no issues.
Just let me know
Yep been there!
Can you click on this link to a Groovy post artical and it will give you full step by step instuctions to get everything out http://www.groovypost.com/howto/firefox/clear-firefox-browsing-history-and-private-data/
Although the instructions are for Windows it will still work in Mac and if you have an issue let me know