Hi,
Thank you for posting your question on Microsoft Community!
After going through your post, it appears that you have an issue with deleting the PDF files. However, in order to guide
you in the right direction; I will need some more information. Please help me by answering the questions mentioned below.
1.
Do you face any issue while deleting the other files?
2.
Which antivirus application are you using?
In-order to fix the deleting the PDF files, you may try these methods.
Method 1:
Keep the computer in clean boot and check the issue status.
How to perform a clean boot to troubleshoot a problem in Windows Vista, Windows 7, or Windows 8.
http://support.microsoft.com/kb/929135
Note: Please go through step 3 of the Kb to keep the computer in normal
startup after fixing the issue.
Method 2:
You can view all programs that are currently running on your computer in
Task Manager.
Check if there is any process running related to the file is running. If you find any, right
click on the process and end it.
Hope this information is helpful. Please do let us know if you need assistance with Windows, we’ll be glad to assist
you!