not work shift for sellect multi filles

[Ghost67]

As this is AntiX, I think the first priority before we can offer help is to determine which file manager the OP is using.
From the screenshot above it would appear to be Rox Filer, which behaves rather differently to (eg) PCManFM or Thunar, so I will defer to someone with more knowledge of Rox than myself :)

[dimzev]

Usually if single-click is configured to open files then hover the mouse cursor over the file without clicking will select. Does hovering the cursor light up the selection rectangle?

when have the cursor over the file nothing happen ...

Do you have a PDF viewer on your system such as qpdfview?

i have install foxitreader but it isnt default ...

[JayM]

Can you tell us which file manager you're using, or at least which window manager? If the file manager has a dropdown menu at the top, click Help then About and tell us what it says.

[dimzev]

Can you tell us which file manager you're using, or at least which window manager? If the file manager has a dropdown menu at the top, click Help then About and tell us what it says.

i think is ROX-filer as file manager...
and icewm
can you give a command terminal to copy results for better?

[caprea]

In the conky (in the upper right corner) it should be shown, which window- and file-manager is used
under Uptime
eg. rox-icewm

[JayM]

OP would get more and faster help if he asked in the dedicated antiX forum as there are a lot of antiX users there who never visit the MX forum, and most of us here actually use MX and not antiX.
https://www.antixforum.com/

[rokytnji.1]

Mouse buttons and keybindings are in the Menu>Help>antix>rox manual

if talking about rox file manager.

Edit: I cruz both forums.

[anticapitalista]

Why not just use Ctrl instead of Shift if it does what you want.

[antiX-Dave]

First
Menu -> desktop -> other desktops -> space-icewm

Second
Menu -> file manager

Then see if the performance is as you expect. This will switch you to a spacefm based desktop rather than a rox based. I suspect that you will be much happier using spacefm over rox filer as it functions closer to other file managers and you are handling multiple files. On top of the shift select function you may also ( for example ) find the split pane function beneficial.