Hi Veasna,
You can try installing the Project Wise Explorer in Clean Boot mode and check.
Follow the KB article to perform clean boot on the computer:
How to troubleshoot a problem by performing a clean boot in Windows Vista and Windows 7
http://support.microsoft.com/kb/929135
Disclaimer: After you have finished troubleshooting, follow these steps from section “How to reset the computer to start as usual after clean boot troubleshooting” to reset the computer to start as usual.
If issue persists I would suggest you to post your query at ProjectWise forum for better assistance:
http://communities.bentley.com/products/projectwise/default.aspx
http://selectservices.bentley.com/en-US/
Hope this helps,