WMS 8.3 did work well with OS windows XP with my former laptop, but now my new PC's OS is Win 7, I even could not successfully install it completely, only the HEC-HMS 3.4 and HEC-RAS 4.0 were installed.I would use the CE-QUAL-W2 module as mentioned. To notice that, at the last of the installation, the installshield wizard showed that WMS 8.3 was installed successfully.However, there is not the WMS 8.3 in the program list. I tried more than three times, it seems the module GSHHA has installation bugs or else.I checked for the operating system requirements, they are windows XP or VISTA, without windows 7. Is it not supported by this relative new OS? God bless me. Has anyone else had ever installed WMS with Win7 OS? If possible, could you share your experience,thanks. I am new with the model , and even now with a brand new computer. It surprised me to met with this confusing problems . Hope things will be fine later .