Open filtered edit form in new window

Here is how you can open any page in a popup:

https://xlinesoft.com/phprunner/docs/how_to_display_any_page_in_a_popup.htm

[size="2"]Thanks you. [/size]
[size="2"]So a popup window is not exactly what I'm looking for. I need it to be a newwindow. PHPRunner doesn't allow you to have multiple tabs open at the same time for differentgrids/forms. I need that ability.[/size]
[size="2"]And I need the ability to Edita user-selected record.
[/size]

Not so clear what you are trying to say when you try to put everything in a short sentence. It is better to break down your sentences clearly, especially when describing what you want to do.
Anyway, I try to guess what you want to do and give some suggestions:

1. "multiple tabs open at the same time for different grids/forms"
   => try dashboard features in PHPR. You can put multiple pages into one dashboard with edit, list add etc. It does not give you multiple tabs, but put different tables (list, edit etc) in a page.
   I think multiple tabs for different tables, may be a good feature request for future PHPR version.
   
2. "open an edit form in a new window filtered on a user selected record. Ideally from a row in a grid"
   => Go to Page Designer, click "View As/Edit As" and choose custom and enter code to show an URL Link:
   eg.
   $value = "<a href='your_page_edit.php?edit1=".$data["your_row_id"]."' target='_BLANK'>edit this record</a>";
   This will present a URL link in your grid, and when clicked, open another browser window for edit page with the record to edit.
   Check the manual for more info.
   ACP

Yeah, I thought about the target='_BLANK and wondering if it would work.
Yes, multiple tabs feature request - absolutely.
The dashboard is good but you need tabs too - it's a real estate issue.
Thanks much.

Your terminology is confusing. The window is commonly referred to as a popup window (my suggestion) or to a new browser window (which you cannot open).
What you looking for a new tab and a link with target=_blank will do that.