Hello Ditta,
It would appear that your installation of XP was damaged to the point that the Product Key updater could not correct all of the problems on the system.
Suggestions:
1. Try to log on using Safe Mode with Networking:
- Restart the computer, and then press the F8 key during startup until the Windows Advanced Options menu appears.
- On the Windows Advanced Options menu, use the arrow keys to select Safe Mode with Networking, and then press ENTER.
- Select Microsoft Windows XP edition, and then press ENTER.
Note In this step, edition represents the correct Windows edition.
- If using the friendly logon, on the To begin, click your user name screen, click your user name and enter the password if using a password; if not using the friendly logon, in the Log On To Windows dialog box, enter your suer name and password if using a password.
- Press ENTER, and then click Yes.
2. Wait for the WGA CD to arrive in the mail and do a repair reinstallation of Windows.
3. Attempt to repair files and registry damage from malware removal that is preventing logon: http://support.microsoft.com/kb/892893
For great advice on all topics XP, visit http://www.annoyances.org/exec/forum/winxp