Whenever I want to open task manager it says "task manager has been disabled by your administrator" can someone please tell me how to enable it?
Thanks in advance :)

Contact your IT department.

You might have a virus or trojan that has caused your task manager to be disabled. To enable the task manager, you will need to modify some registry settings, if you feel comfortable enough to do so. Please keep in mind that modifying the registry can cause adverse effects on your system, so create a restore point, and save a back-up of your registry before making any changes. DO NOT make any of these changes if you feel uncomfortable about it.

Click Start -> Run. Type in "regedit" (no quotes) and hit Enter.

Search for HKEY_CURRENT_USER -> Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ System.

Look for: DisableTaskMgr. Value: 1=Enable this key (disables TaskManager); Value: 0=Disable (actually enables TaskManager), So, you'll want to make sure the value is 0.

Close RegEdit and reboot your machine.

If you have any other problems after your computer reboots, then do a system restore. Scan your system for any viruses or trojoans as well. Hope this helps!