Set 16x9 resolution for guest

[Errol]

I am running VB 5.2.8 on my Windows 10 PC. I have dual screens, both running at 1600 by 9 resolution.
I have Windows 7 as a guest system but I cannot select 1600 by 900 resolution in Win7. Only 4x3 resolutions.
Any way to do this? Have tried File, Preferences, Display, Hint and typed in 1600 by 900 but this does not work!

Many thanks

Errol

[mpack]

VirtualBox will set any display size the guest asks for, so the trick is to convince the guest to ask for a widescreen ratio, even though it thinks it currently has a 4:3 monitor.

In the VirtualBox manager, set File|Preferences|Display|Max Guest Screen Size to None. Then start the guest, waits until it's finished booting, then drag the guest window border to a widescreen ratio then shutdown and boot again. Hopefully the guest now displays widescreen monitors. If not then go into the advanced display options (in the guest) and force your choice.

[Errol]

Tried the first method, but when I rebooted, it was still in 4x3.
Then tried (in the running guest system - Win 7 in this case) Display - Advanced etc, but still no option to select any 16x9 formats.
Maybe my dual screen video card is the problem, and I should just plug in one of the screens to the motherboard video plug? What do you think?

[mpack]

Your host monitor is not relevant, as that is not attached to the virtual machine. I know that the methods I outlined earlier work, because I do it regularly myself and have never had a problem.

[jorgensen]

Have tried File, Preferences, Display, Hint and typed in 1600 by 900 but this does not work!

Doesn't seems to work.

VBoxManage controlvm "Guest name" setvideomodehint 1600 900 32
should work, otherwise reinstall guest additions.

[mpack]

Setting a mode hint does not force the guest to choose that resolution.