I recently installed Debian Trixie on a brand new computer I built out
myself. Intel Core Ultra 7 265K CPU, MSI Pro B60M A WF motherboard.

The installer told me that it needed additional firmware files to be
able to use my WiFi adapter:

  Some of your hardware needs non-free firmware files to operate. The
  firmware can be loaded from removable media, such as a USB stick or
  floppy.

  The missing firmware files are: iwlwifi-gl-c0-fm-c0-93.ucode

  If you have such media available now, inset it, and continue.

  Load missing firmware from removable media?

I found that file online, put it on a thumb drive with VFAT
formatting, stuck it in a USB port, and replied yes to the above
prompt. The installer proceeded without prompting me again for the
firmware, so I assume that it found the needed file on the thumb drive
and loaded the firmware successfully.

However, after that, _it did not prompt me for which WiFi network to
use or for the password for that network_. It just went into
"Detecting Link", which failed, then asked me which interface it
should use as the primary. I told it to use the WiFi interface, which
it again tried unsuccessfully to detect link on (since it never
prompted me for the WiFi network info!), then tried to use DHCP to
connect which also failed, then told me that it couldn't connect to
the network and offered to let me proceed with the install without a
network connection.

Note that when I boot from a Debian Trixie live image straight into
GNOME running from the thumb drive, I _am_ able to connect to the WiFi
network by opening the GNOME menu from the top right corner of the
screen and clicking on WiFi. So Trixie _is_ capable of connecting to
my WiFi using the controller in my new computer; it's just that the
installer isn't.

(Note, the above occurred with both the graphical and text installer.)

(...)

Without installing the firmware file you mentioned above ? It is not
present in the firmware-iwlwifi package, so it should not be present in
the live image either.

This may be a duplicate of bugs #1095302 and #1103993 (netcfg does not
support Wi-Fi 7 devices).

What is the wireless controller model ?
Can you do a quick test in the live system ?
Run the command "/sbin/iwconfig" and check if it reports wireless
extensions on the wireless interface wl*. You need to install the
package wireless-tools if the command is missing.

The internal logic is the same, only the interface differs.

Correct, the Debian live thumb drive never prompts for for the firmware
file and still successfully connects to the WiFi.
Quite possible, since I believe that the WiFi device provided by my
motherboard / CPU combination is a WiFi 7 device.

It reports "no wireless extensions" for the wlp131s0f0 device.

   jik

Can you check kernel logs with `sudo dmesg|less` and look for lines
about firmware and (iwlwifi or the wireless device bus ID) ?

This explains why the installer does not identify it as a wireless
device. Both iwconfig and netcfg use the legacy wireless extensions API
(wext) but it seems that Wi-Fi 7 devices can only be used via the newer
nl80211 API (used by iw and NetworkManager), not via the wext API.
Adding nl80211 support to netcfg will probably be a post-trixie goal.

 From /var/log/syslog:

2025-07-26T19:49:56.969785-04:00 jik7 kernel: pci 0000:83:00.0:
[8086:272b] type 00 class 0x028000 PCIe Endpoint
2025-07-26T19:49:56.969785-04:00 jik7 kernel: pci 0000:83:00.0: BAR 0
[mem 0xb8000000-0xb8003fff 64bit]
2025-07-26T19:49:56.969785-04:00 jik7 kernel: pci 0000:83:00.0: PME#
supported from D0 D3hot D3cold
2025-07-26T19:49:56.969887-04:00 jik7 kernel: pci 0000:83:00.0: Adding
to iommu group 21
2025-07-26T19:49:56.970174-04:00 jik7 kernel: Intel(R) Wireless WiFi
driver for Linux
2025-07-26T19:49:56.970175-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
enabling device (0000 -> 0002)
2025-07-26T19:49:56.970176-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
Detected crf-id 0x2001910, cnv-id 0x2001910 wfpm id 0x80000000
2025-07-26T19:49:56.970177-04:00 jik7 kernel: iwlwifi 0000:83:00.0: PCI
dev 272b/00f4, rev=0x472, rfid=0x112200
2025-07-26T19:49:56.970177-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
Detected Intel(R) Wi-Fi 7 BE200 320MHz
2025-07-26T19:49:56.970179-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
TLV_FW_FSEQ_VERSION: FSEQ Version: 0.0.4.190
2025-07-26T19:49:56.970179-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
firmware: failed to load iwl-debug-yoyo.bin (-2)
2025-07-26T19:49:56.970179-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
firmware: failed to load iwl-debug-yoyo.bin (-2)
2025-07-26T19:49:56.970179-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
firmware: failed to load iwl-debug-yoyo.bin (-2)
2025-07-26T19:49:56.970180-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
loaded firmware version 93.c5af2ca2.0 gl-c0-fm-c0-93.ucode op_mode iwlmvm
2025-07-26T19:49:56.970188-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
Detected RF FM, rfid=0x112200
2025-07-26T19:49:56.970188-04:00 jik7 kernel: iwlwifi 0000:83:00.0:
loaded PNVM version 8af7618d
2025-07-26T19:49:56.970189-04:00 jik7 kernel: iwlwifi 0000:83:00.0: base
HW address: e0:8f:4c:b0:f6:d5
2025-07-26T19:49:56.970189-04:00 jik7 kernel: iwlwifi 0000:83:00.0
wlp131s0f0: renamed from wlan0
2025-07-26T19:49:57.088090-04:00 jik7 NetworkManager[1816]: <info> 
[1753573797.0880] rfkill1: found Wi-Fi radio killswitch (at
/sys/devices/pci0000:80/0000:80:1c.3/0000:83:00.0/ieee80211/phy0/rfkill1)
(driver iwlwifi)
2025-07-26T19:50:01.107402-04:00 jik7 ModemManager[1815]: <msg>
[base-manager] couldn't check support for device
'/sys/devices/pci0000:80/0000:80:1c.3/0000:83:00.0': not supported by
any plugin

Well that definitely confirms the Wifi 7 part.