|"but no key combinations allow me to click my icon to enter my password"|
I did assume a few things here, but rather than do that, here are other possibles. When you get it back to normal, make sure you have SP3, it fixes a lot of this type of issues.
You cannot type your password in the "Welcome" logon screen in Windows XP
When you try to log on to a Windows XP-based computer from the Welcome logon screen, you cannot type your password. For example, when you click in the password box, and then you try to type the password, nothing happens. Asterisk characters do not appear in the password box, and the password is not acknowledged. Because of this problem, you cannot log on to the account by using password authentication. This problem may occur only occasionally.
To work around this problem when it occurs, temporarily use the classic logon screen to log on. To do this, follow these steps:
1. Press CTRL+ALT+DEL two times while the Welcome screen is displayed. For example, press all three keys at the same time, release all three keys, and then press the three keys again.
2. Type your account name in the User name box.
3. Type your password in the Password box.
4. Click OK.
You can configure Windows XP to always use the classic logon screen. For more information about configuration changes, click the following article number to view the article in the Microsoft Knowledge Base: 291559 (http://support.microsoft.com/kb/291559/ ) How to change the logon window and the shutdown preferences in Windows XP
Press tab twice, if focus moves, but no blinking cursor...keep pressing tab numerous times and trying to enter without password by clicking on the green arrow. XP may freeze,...press ctrl+alt+canc to use normal logon window and it may still be frozen, with only the cancel button not gray.
Wait and see if it comes back to normal, then enter username and password.
How to Hack a Window XP Admins Password
I found this to be a good download site.
More possibles here.
How to Bypass Windows XP Password in Safe Mode?
CHKDSK using the XP CD & Windows XP Recovery Console
Running CHKDSK from the Windows CD
chkdsk drive /p /r
Offline NT Password & Registry Editor
* This is a utility to reset the password of any user that has a valid (local) account on your Windows