My Dell is E520.
And to the guy who said about that BIOS,yes i changed it to that,but than it was not able to boot from the hard disk ,so i changed to default

One more thing.
I did a Express Test of the hardware with Dell Resource CD,and this time it passed all the tests:
http://i11.tinypic.com/53582zl.jpg

But today morning i did the same test again and i got those errors:
http://i13.tinypic.com/62xq4nk.jpg

But this time i managed to see the end of the errors,you see that line:
"F:\DIAGS\DIM 32\A1279"

And just to remind you that the current Danish windows works without any problem,all my programs,files ,folders work just great.
Because i can see most people scan their hard disks for bad sectors,when they have serious problems like:The pc doesn't boot from the hard disk,they get these blue screens when they starts the pc,their pc boots after they turn it on,they have problems running programs...,and i don't/didn't have such problems.
My only problem is Installing other windows except the one that came with my Dell.
And this errors during hard disk tests.Could it be that the resource cd is damaged?

Im happy to tell you that my problem is SOLVED.
Yes,the whole trick was changing SATA Operation to AUTO DETECT,and booting right away from cd,not from hard disk.Last time when i tried this ,i continued booting from hard disk but i got the blue screen,while this time i did those changes on the BIOS,and i choosed to boot from the cd,and it worked!
Also the errors during Express Tests from the Resource CD ,seems to be fixed now.I did two tests and i didn't got those errors at all!

I would like to thank you very much for helping me(especially GioAguilar),and i will make sure everytime i have something to ask about my Dell,this will be the first place i will come.

:)