Resolution problem when switching from 27" to 15" and back-Could not start

[europanorama]

Had to switch to 15" crt-screen to run a special program. 768x 1024/75hz which worked. I had set down resolution before shutting down 27" beforehand.
but when going back to 27"(i didnt change resolution) a warning came 1024 x1920/60 Hz needed.
Tried to alter resolution in safe mode which worked but only to 1024 x1600.
still the same warning.
At the end i did a system restore but i had lost a program installation.
What went wrong?

[Train]

If you failed to shut down before switching monitors, The drivers got all fouled up.

[europanorama]

Sorry booting was possible but screen blank except the resolution warning.
I forgot this important fact.
Until some time back i used 17" screen(also used it tonight) for that test and never had this problem. But the only 17" screen i have left seems now defective(bad image). surplus good screens(all were good) thrown away....
maybe i should test with second good drive. this one has sometimes a bluescreen problem with reboot, not always but often aec.sys problem. we discussed that, could be a videocard-driver problem since i switched videocard when switching drive too.
i could not display nvidia systemcontrol in safe mode.

[Train]

Possibly.

[europanorama]

The idea was to use the interface which allows changing settings only after restart-during that i had replaed the monitor( from 15 to 27" with HR. but i didnt see in display-setting, why?

[Train]

Failed to see it. reboot worked for me as it found the monitor on the 2nd boot up.

Forgot that happened to me.
Need to know this trick when things get messed up

Press Ctrl+Esc key or the Win key and press u two times - the fastest approach.

I used also. flag key, r-arrow key twice and hit enter. Maybe one R-arrow key off so watch what happens and when shutdown shows up, hit the enter key and it wil shut down. What I normally used anyway.

[europanorama]

I used reset-switch to restart with working monitor or whatever reboot when screen was blank.
btw: on newer pcs where is the reset-button. i dont see any other than power.

2. have found the trigger to set resolution to be set after restart. its is set to act immediately. its in extension of display-menue. we will see next time. will so prepare new resolution always on wrong screen. should work. winxp

[Train]

Using the power Button has been know to scramble xp so it will not boot again.

[europanorama]

More than once i had to repair the winxp-system, above all after power-button-shutdown when i forgot the reset...pc is outside so i always have to search which if the multiple buttons of 2 pcs is the right one....

so you want to say with win7 there is no need for a reset-button, right?

[Train]

Never have used a reset button.