Can I open/view wmf files in Photoshop Elements?
If so, how?
No.
There are a couple of crummy free plugins somewhere, or you can open in
other programs, save as TIFF/JPEG, etc. Or Copy/Paste.
Most all these methods only allow very low rez raster conversions (WMF is
usually a vector file format, although it can be either, or both).
Best way is to open in a proggie like Illustrator or CorelDraw that
allows saving in .ai or .eps format. Then open those in PS, at which
point you can choose how high a rez at which to rasterize them.
Mac