A couple of questions; WinXP Home

I managed to reset my 'hidden' Admin password on a Dell Dimension E521 that came with preloaded WinXP Home.

When I did so, I changed an account on to a limited one. In safe mode, that user no longer shows up as extant when I go to user accounts, though it does show up on the main screen to sign in on regular start up. I'd like to be able to have the flexibility to change any other options on this account before it gets deleted (transfer files, etc). What could have happened?

The other issue is I need to block Yahoo IM or other IM services & don't know the steps to make this happen. Yahoo gives the following info:

Do I need to sign in through safe mode and configure firewall settings?

Thanks in advance for help anyone gives.

For you cross-forum members, this was posted on Tech Support Guys also. Looking for any assists I can get.