Windows 10 has many advantages over its previous versions. But it was reported that there're also many issues.
As per the query, you have issues with some programs opening twice in Windows 10 Insider technical preview.
I would suggest you to check the system files are they working fine or not and to check that try to run System File Checker (SFC) tool.
SFC scan will scans all protected system files and replaces incorrect versions with correct Microsoft versions.
How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows 8.
Press Windows key and X at the same time.
Choose Command Prompt (Admin) from the context menu.
In the command prompt, type sfc /scannow and hit Enter.