Windows 2000 logon problem

I have installed Windows 2000 and it works pretty fine, until I installed an Iomega Zip drive, so after restarting W2K, it took so long the process of restarting, and at the end, even if all seems to be right, when I try to access the logon windows pressing CRT+ALT+DEL nothing happend. Do you have an idea of what happend or If there is a way to fix this problem. Thanks