windows freeze on scan and repair

Method 1: 

Perform an Automatic repair using Windows 8 bootable DVD or USB drive and check if that helps.

Follow these steps to perform Automatic repair

1.     Insert the installation DVD or USB and boot Windows 8 from it.

2.     In the ‘Windows setup’ page select the ‘Language to install’, ‘Time and currency format’ and the ‘keyboard or input method’ and click on ‘next’.

3.     Click on ‘Repair your computer’ and select ‘Troubleshoot’.

4.     Click on ‘Advanced options’ and select ‘Automatic Repair’ and select the operating system.

Method 2:

Try booting the computer in safe mode and perform a clean boot. 

Step 1: Perform Safe Mode 

There are two ways to get to the Windows Startup Settings screen in Windows 8 :

·         If you're not signed in to Windows, tap or click the power icon   from the sign-in screen, hold Shift, and then tap or clickRestart

·         Or, if you're already signed in:

1.  Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.(If you're using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, click Settings, and then click Change PC settings.)

2.  Under PC settings, tap or click General.

3.  Under Advanced startup, tap or click Restart now.

4.  On the Choose an option screen, tap or click Troubleshoot.

5.  Tap or click Startup Settings.

6.  Tap or click Restart.On the Startup Settings screen, choose the startup setting you want.

7.  Sign in to your PC with a user account that has administrator rights.

Step 2: Perform Clean Boot.

• Windows 8

1.     Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search.

2.     Type msconfig in the search box, and then tap or click msconfig.

3.     On the Services tab of the System Configuration dialog box, tap or click to select the Hide all Microsoft servicescheck box, and then tap or click Disable all.

4.     On the Startup tab of the System Configuration dialog box, tap or click Open Task Manager. 

5.     On the Startup tab in Task Manager, for each startup item, select the item and then click Disable. 

6.     Close Task Manager.

7.     On the Startup tab of the System Configuration dialog box, tap or click OK, and then restart the computer.

• Windows 7 and Windows Vista

1.     Log on to the computer by using an account that has administrator rights.

2.     Click Starttype msconfig.exe in the Start Search box, and then press Enter to start the System Configuration utility.

If you are prompted for an administrator password or for confirmation, you should type the password or provide confirmation.

3.     On the General tab, click the Selective startup option, and then click to clear the Load startup items check box. (The Use Original Boot.ini check box is unavailable.)

4.     On the Services tab, click to select the Hide all Microsoft services check box, and then click Disable all.

Note This step lets Microsoft services continue to run. These services include Networking, Plug and Play, Event Logging, Error Reporting, and other services. If you disable these services, you may permanently delete all restore points. Do not do this if you want to use the System Restore utility together with existing restore points.

5.     Click OK, and then click Restart.