Problems installing Mac OSX on iMac with damaged display

Hello, good afternoon to you all!

This is my first post on this forum, and i would really appreciate to get some help on this!

I've got an iMac, 1.83 Ghz Intel Core Duo (The white ones) and i'm trying to update the OS from Leopard to Snow Leopard and, at the same time format hard drives and leave it clean and fresh.

This serie of iMacs came with a defect on the display and it is no longer working, just colored stripes and damaged pixels going on, so i must use this mac with an external display and it works flawlessly this way. (I don't use mirror desktops, but extended desktops as the resolution of the external display is different than the imac's one)

The big problem i have is that when i tried to reinstall the system i noticed that in some point of the installation it sets the imac's display as the main one, instead of the external display and obviously the finder and everything goes back to the damaged imac's display, making it impossible to continue.

The question: Is there any way i could do this and keep my external display as the default? Maybe some shortcut to switch between mirror and extended desktops or something like that??

Thank you very much in advance, i've been looking on a lot of forums about this and haven't found a solution yet!

It's not possible with the iMac (at least with the one you have). If you had a MacBook or MacBook Pro it could be done but not with your iMac. Why don't you replace the display? According to Mactracker, your machine is a 2006 17" model so maybe it's time to buy a new one?

I've got 2 new ones, but it is incredible for me that it is not possible to do this without replacing the screen on my oldie, i basically want this mac to work for browsing the web and basic stuff and leave the new ones just for work. So this means there is no other solution than throwing it to the trash of replacing the screen on it? ****!

I've jjust browsed the web looking for prices on replacement screens for my imac and the prices go as crazy as 600 US$ Not sure if the entire system working would cost as much as that :S I need a solution pleaseeee someone??

Where did you look for the display? If you went to authorized Apple service centers and parts, you'll likely pay a premium price. Try eBay first to see what they want. Another thing is the 17" iMac display is hard to find and that drives up the price.