System randomly deletes application dlls??

I have an infuriating problem with my Dell Vostro 1720 laptop ever since upgrading from Vista Pro to 7 Pro.

Randomly, without any interaction from me, application dlls just go missing. I can install an application one day, and the next, when I try to launch it, I will be prompted with "XXXYYY.dll is missing"

The PC is virus and spyware free and I've applied all Windows updates.

I tried a full repair install of Windows 7 Pro using the CD and the "Upgrade" option, and whilst this did fix the problem temporarily, withing a couple of weeks, the problem was back!

Has anyone else come across this, and can anyone offer any advice? As you can imagine, it is a right pain in the backside!!


Excellent Member
Microsoft Community Contributor
Is it always the same dlls and what program are they related to? Do you have any idea as to when they might be disappearing?

Are you running any cleaners that might be erasing files they think are unused?

Anything in Event Viewer about software or those particular files that might indicate the problem?

I am assuming that these dll files are in your program files folder.

Check the security tab on your program files folder to see if anything is out of the ordinary.

Take ownership and Change it temporarily so that nobody is able to have full control, write access, or special permissions. You will need to give the system group read & execute to be able to run your programs.

You may have some malware.

Here is a tutorial on how to add take ownership to your right click menu for files and folders:Add "Take Ownership" to Explorer Right-Click Menu in Win 7 or Vista - How-To Geek


Last edited:
This website is not affiliated, owned, or endorsed by Microsoft Corporation. It is a member of the Microsoft Partner Program.