How come I cant run as admin for programs in windows 8.1 and cant open file explorer.

To run a program as administrator, you have to right click on the application and select Run as administrator. It might ask you for administrator password, enter it and then open the application as an administrator.

If you are unable to open file explorer, then I would suggest you to run the sfc/scan and check.

The sfc /scannow command scans all protected system files and replaces incorrect versions with correct Microsoft versions. When the scan is complete, the System File Checker tool indicates whether integrity violations were found. If integrity violations are found, the System File Checker tool lets you fix the integrity violations. Refer to the following article to know how to do this.

Use the System File Checker tool to repair missing or corrupted system files

http://support.microsoft.com/kb/929833

I would also suggest you to check the event viewer at the time of failure.

Event Viewer is an advanced tool that displays detailed information about significant events on your computer. It can be helpful when troubleshooting problems and errors with Windows and other programs.

To get to event viewer in Windows 8:
a. Go to the Start Screen. Type in Event Viewer.
b. This will bring up the Event Viewer box. Click to open the event viewer.
c. In the left pane, expand out Windows Logs.
d. Click on Application log. Highlight the first event in the log and use your arrow keys to scroll down. Most of your event will be Information. You may see Yellow Warnings or Red Errors. If you see a red error, you can double click on it to bring it up and copy the contents to a document.