If you can't log in to your PC it may be due to a few things.
Check your network cable, it may be loose or disconnected. This would stop you from getting in.
If your PC connects to your phone, check the cable at both ends to make sure it's firmly connected.
Your account may be locked or your password may have expired, you can test this by trying to log into a colleagues PC with your details.
If your account has been locked or your password has expired, you won't be able to log in to your own PC.
There are a few steps to resolve this. Using a PC that is already logged into,such as a colleagues, visit https://password.cit.ie.
Use the password self-service to change your password and/or unlock your account.
If you're unable to complete the password self service, please ask a colleague to email in a password/account reset request on your behalf, quoting your name and staff number. The call will be handled through your colleagues email account.