A question that I often get asked is "Do you know of a utility that will show me which DLLs are loaded on Windows 9x or NT?". The answer I gave up until recently was "no", until I discovered a tool in the Windows NT Resource Kit called tlist that does show this information. I decided to write a free-ware version, ListDLLs. Unlike tlist, however, ListDLLs is able to show you the full path names of loaded modules - not just their base names. In addition, ListDLLs will flag loaded DLLs that have different version numbers than their corresponding on-disk files (which occurs when the file is updated after a program loads the DLL), and can tell you which DLLs were relocated because they are not loaded at their base address.
You can also get Process Explorer, a GUI-based version of this program, here at Sysinternals.
Just copy ListDLLs onto your executable path, and type "listdlls".
ListDLLs works on Windows 9x, NT 3.51, NT 4.0, and Win2K.
The following Microsoft KB articles reference ListDLLs for diagnosing or troubleshooting various problems: