Operating System not found

[galanh]

Hi

I installed Ubuntu 10.04.1 on a Dell studio with i7 processor
I restarted the machine twice to Ubuntu and then I boot Window7.
Windows7 did a 3-step check of the hard disk new space and started.
The anti-virus started and did a global check.
I re-started again the machine and the following message appeared:

no module found
Aborted. Press any key to exit
Intel UNDI, PXE-2.1 (build 083)
.................................................. .............................
PXE-E51 No DHC or proxy DHCP offer were received
PXE-M0F-Exiting PXE ROM
Operating System not found

Thanls for any help

[galanh]

Window7 disable my boot loader.
I am running my Ubuntu 10.04.1 without problem.
Even I can boot Window7 if I restart my computer.
But after restart from Window7 I have the following message:


no module found
Aborted. Press any key to exit
Intel UNDI, PXE-2.1 (build 083)
…................................................. .......
PXE-M0F-Exiting PXE ROM
Operating System not found


Without operating system I need to use again my CD to reinstall 10.04.1
I don't know how to get out from this point.



I ran the following scrip:

Boot Info Script 0.55 dated February 15th, 2010

============================= Boot Info Summary: ==============================

=> Grub 2 is installed in the MBR of /dev/sda and looks on the same drive in
partition #5 for /boot/grub.

sda1: __________________________________________________ _______________________

File system: vfat
Boot sector type: Dell Utility: Fat16
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files/dirs: /COMMAND.COM

sda2: __________________________________________________ _______________________

File system: ntfs
Boot sector type: Grub 2
Boot sector info: Grub 2 is installed in the boot sector of sda2 and
looks at sector 948745976 of the same hard drive for
core.img, but core.img can not be found at this
location. No errors found in the Boot Parameter Block.
Operating System:
Boot files/dirs: /bootmgr /Boot/BCD

sda3: __________________________________________________ _______________________

File system: ntfs
Boot sector type: Windows Vista/7
Boot sector info: No errors found in the Boot Parameter Block.
Operating System: Windows 7
Boot files/dirs:

sda4: __________________________________________________ _______________________

File system: Extended Partition
Boot sector type: -
Boot sector info:

sda5: __________________________________________________ _______________________

File system: ext4
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 10.04.1 LTS
Boot files/dirs: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img

sda6: __________________________________________________ _______________________

File system: swap
Boot sector type: -
Boot sector info:

=========================== Drive/Partition Info: =============================

Drive: sda ___________________ __________________________________________________ ___

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start End Size Id System

/dev/sda1 63 80,324 80,262 de Dell Utility
/dev/sda2 * 80,325 30,800,324 30,720,000 7 HPFS/NTFS
/dev/sda3 30,800,325 529,014,566 498,214,242 7 HPFS/NTFS
/dev/sda4 529,014,782 976,773,119 447,758,338 5 Extended
/dev/sda5 529,014,784 958,537,727 429,522,944 83 Linux
/dev/sda6 958,539,776 976,773,119 18,233,344 82 Linux swap / Solaris


blkid -c /dev/null: __________________________________________________ __________