Thank you for posting your query in Microsoft Community.
From your issue description I understand that you are getting SFCOM.DLL error after upgrading from windows 7 to windows 8.
In order to help you better please provide us the following information:
1) When exactly do you get the error message?
To fix the issue with SFCOM.DLL error you can follow these steps: Method 1: Perform System File Checker
a) Press the Windows + X keys and click/tap on Command Prompt (Admin).
b) In the elevated command prompt, type sfc /scannow and press Enter.
NOTE: This may take a while to finish running.
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
Method 2: Scan for system using Windows Defender
I would suggest you to scan the system for malware using Windows Defender or virus software installed on the computer.
a) From the start screen, type Defender.
b) Tap or click Defender from the results.
c) To the right, change the Scan options to Full.
d) Tap or click Scan now.
e) If any infections are found you will be asked to remove or quarantine the item. Follow the instructions on the screen for removing the infected items.
Method 3: Clean Boot.
Perform clean boot to identify if any 3rd party service is causing this issue: http://support.microsoft.com/kb/929135?wa=wsignin1.0 Note: After performing the troubleshooting steps in clean boot, follow Step 3 from the link to start the computer to Normal start up mode.
For any Windows related assistance in the future, feel free to contact us and we will be glad to help.
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