The File should have downloaded with the RHI extension. If not, then rename the ZIP extension that your browser has modified. Once it is has the correct extension of RHI then you can double click and it will start the installation process

The screen shot shows the contents of the zip file. i have even renamed the zip file with a RHI extension, but there is no change. Its the first time I am encountering such an issue.

Thanks for your help Danny

You haven't renamed the extension it is still a zip file.

All you have done is rename the file to include .RHI

Go to the Organize Drop down Menu (just above the Folders Window on the Left hand side)

Select Folders and Search Options and click the VIEW tab.

Scroll down the list and un-tick the box marked "Hide extensions for unknown file types"

This will allow you to rename the extension properly. You may receive a warning that the file may not behave properly after doing so but proceed anyway.

Hi Danny,

Thanks for the info.

Can you guide me through the next steps. I restarted my PC and checked, Grasshopper is still not installed. and I did not even get the ghx "green" installer screen while installing the rhi file. Sorry for being annoying.

That's ok.

When you run the grasshopper command in Rhino. What message do you get?

unkown command : Grasshopper

Can you do a search in windows for "*.gha"

It appears that the location for these files is a server... is that correct? 

Are you able to install it on your local drive?

yeah its my company server. I cannot install it on my local drive but if there are set of instructions to follow, My company IT can do it for me.

It probably doesn't matter.

The location of my installation is:

C:\Program Files\Common Files\McNeel\Rhinoceros\5.0\Plug-ins\Grasshopper (b45a29b1-4343-4035-989e-044e8580d9cf)\0.9.64.0

Can you go to the Options page in Rhino TOOLS>OPTIONS and select Plug-ins from the left hand tree view.

Then Click Install and navigate to the above location (it will say 0.9.66.0 probably)

then select the RHP file and OK 

If it isn't there then go to the location from your search which starts 

\\faeaua10000.wsatkins.com\aeauahome$\sawl54....

and do the same as below

Its not there in the first location and the second location is just referrring back to my desktop where i had unzipped the downloaded file.

\\FAEAUA1000.wsatkins.com\AEAUAHome$\Sawl5491\Desktop\grasshopper_0...

Also, I was thinking to copy the whole unzipped Grasshopper folder to Rhino 5--> Plugins and then install the.RHP file from within Rhino.