Monitor Problems

This may not be a problem with my Dell laptop, but rather a Windows issue but it is a Dell laptop so here goes....

Dell Inspiron 1525 running Windows Vista Home Premium.....

I've been having an issue with my laptop display not working properly. It seems to have all started after I connected my laptop to our new plasma tv via an ordinary "video" cable. Since then, whenever I turn off the laptop (I rarely turn it off, but have had to restart due to several McAfee software updates) when the computer reboots, the screen is blank. I see some trailing lines, but no image. If I connect to an external monitor, I can see my computer. The only way to get the laptop monitor back is to power down the laptop, plug in the external monitor and turn it back on. At this point, the display will appear on the external monitor and my laptop monitor. Now I can disconnect the external, but as soon as I turn off the laptop, there will be no screen. The first time this happened a did a hard restart (no power, no battery, press the power button for 30+ seconds) and when I restarted the laptop, the monitor came back. On subsequent attempts with this method, I have not had success. As it now stands, the only way to get the display back is through the steps I described before. How can I fix this problem? I'm almost ready to throw in the towel and reinstall windows.

Vista is up to date and I have tried the Fn + F8 key. When I do this with the external monitor connected, it cycles through notebook only, external only, notebook and external, however, the laptop monitor never comes on.

When I pull up the display settings, it shows two monitors in the diagram. The larger one is my laptop. The dropdown list below it says

Generic PnP Monitor on Mobile Intel(R) 965 Express Chipset Family

The check boxes below it are both checked and grayed out
x this is my main monitor
x extend my desktop onto this monitor

There is a second option in the dropdown list that says

(Default Monitor) on Mobile Intel(R) 965 Express Chipset Family

If I select this, the second, smaller monitor picture highlights and the checkboxes below, the first is unchecked and grayed out, but the second is unchecked but active. I haven't tried it yet, but would checking that do anything?

Also, when I click the button to "Identify" the monitors, my laptop is 1 and when I had the external attached it was 2.

Would this be the Generic PnP Monitor listed under 'Monitors' or Mobile Intel Chipset under 'Display Adapters'

I was a little discouraged at first, but that seems to have done the trick. I uninstalled and then reinstalled the Intel driver and upon restart, there was no laptop monitor. I hauled out the external monitor again, hooked it up so I could see to power down and restart and the laptop monitor was good. Restarted 2 more times and it has come on each time so I think it is fixed!

A bit off topic, but follow up to a comment earlier... how hard is the upgrade to Windows 7? Anything I should be concerned about?? My laptop is about 2 years old, would it be worth the cost of an upgrade or should I hold out and buy a new laptop with Windows 7 in another year or so??

Small correction....this didn't work. Shutdown later last night and when it re-booted, the laptop screen did not come back on and I couldn't get it to come on using any of the techniques I had tried before. I have since restored the pc to before I uninstalled the Intel driver and I'm still unable to get the notebook monitor to come on. I still have the black streaks, so I know the monitor is "on", just no picture. Any other thoughts? This does sound like, to me anyway, a hardware issues, so will reinstalling windows (vista) fix this?

I am truly at a loss here. I tried to re-install Windows Vista using the "upgrade" option where it keeps your files and settings and after wasting away another afternoon, I have accomplished nothing. I am still unable to use the laptop monitor. My last effort will be to do a clean install of Windows. I need a little advice first, however....

First off, since I can't use the laptop monitor, if I do the install with the external monitor connected, will this have any long term effects on the installation (in other words, will windows install thinking that the external is the primary monitor and do something different with the laptop monitor)?

Second, can I/should I do the installation with or without formatting the hard drive. In earlier versions of windows, whenever I reinstalled windows, I would generally run fdisk and format the hdd before the installation. I would rather not do this if its not necessary as it consume a lot of time. Would I have better results if do?

Lastly, are there any other things I should be looking at before this step? I can't believe that re-installing the OS isn't going to fix a non-hardware issue. I looked in the BIOS at setup but didn't see anything that might be problematic or that even pertains to monitor/display issues.

On one of the restarts the laptop screen came on with the external monitor, but since then I've only been able to get the black screen with streaks of gray??

During the re-installation. I think it was actually before windows was reinstalled. It re-started to the installation screen and both the monitor and external were visible, but on the next restart, only the external came back. What I'm wondering is that, with the "upgrade" installation, all of the drivers are still installed. I didn't have to re-install any monitor or display drivers, so I'm wondering if a clean install might fix things.

I have officially written off this laptop. I did a complete (clean) install of Windows and nothing has changed. All of the hardware drivers have been installed and updated with no solution. Thus, I suspect you are right in calling this a hardware problem. I still can't understand how, though. When I was able to get the laptop monitor to work, it continued working without any trouble until I would restart the computer. I could close the lid and open it immediately, close it and reopen in the morning. It didn't matter, the monitor would work until I restarted.

Anyway, the weird thing I am noticing is in the Display Settings dialog, the computer continues to make the external monitor the #1 monitor. I can change all of the settings and make the notebook monitor #1, the primary monitor and apply the settings, but when I restart the computer, it will flip back to #2.

I appreciate your help, and perhaps you will join me in one of my soon to come threads when I try to build a new laptop to order in the next few days!!