dwm.exe is a program which is most likely legit. So, if dwm.exe is on your PC, it is most likely ok, and will NOT be a cause for concern. Even if your system is clean, we still advise you to purchase a good antivirus with a good track record, in order to yourself yourself against viruses and malware.
Usually, this program is found in C:\Windows\system32\dwm.exe.
The MD5 checksum for this executable is 81fc187b779d59e4fd2f646bb03ebf03.
This program does NOT run as a Windows service. This is usually a good sign.
dwm.exe seems to have something to do with Windows SFC (System File Checker) or Windows File Protection.
This is a x64 executable. It uses the full capacity of modern CPUs.
dwm.exe appears to have a visible user interface. This means it doesn't run in some kind of stealth mode. Its operation is clearly shown to the user.
dwm.exe is digitally signed. Today most clean software applications are digitally signed.
The digital signature found in dwm.exe is valid. This is excellent.
Digital certificate name: Microsoft Windows
Certificate's issuer name: Microsoft Windows Production PCA 2011
This program does NOT have an uninstall command set up in registry.