Reinstalling Windows 7 Pro on a Dell Precision 3510

Company gave me a hand-me-down Dell Precision 3510. Takes literally minutes to boot up. When I press Ctrl-Alt-Delete, it takes literally minutes to give me the logon screen. I type in my username and password. Again, tens of minutes pass by before I get the desktop. With huge icons. IT doesn't want anything to do with it, and tells me to blow it away.

Tried to see if I can restore the laptop to a proper state. Boot up and press F8 to access the Advanced Boot Options menu. Click on "Repair Your Computer". Windows then loads some minimal files to boot up. Choose your language, log in as Administrator, and then you're presented with a choice of System Recovery Options. System Restore is not going to help as there were no previous restore points. System Image Recovery also won't help as no backup system image was created or found. So looks like we'll have to use the Dell Factory Image Restore option (usually the last item on the list).

The tool then goes about reformatting the hard disk and flashing the stored factory image from the recovery partition. In my case, the restoration always fails at the 63% mark. I guess the factory image is borked. Next up, the Dell OS Recovery Tool.

With this software, you simply provide the service tag, and it will download the appropriate Dell recovery image and burn it to a USB stick (at least 8GB) that you provide. Boot up the laptop, press F12 to change the boot order, and select to boot from the USB stick. In my case, the USB prep kept on failing. The tool would start writing the downloaded 7GB image. During the last few seconds (after half an hour or so), it would complain that something has changed and starts the process again, ad infinitum.

After half a day of trying, it was only after I switched to a SanDisk USB stick that the burn completed successfully.

Next problem. According to this, I was supposed to install Windows on the primary partition, but Windows says no. "Windows cannot be installed on this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only installed on GPT disks." Simplest solution is to delete all existing partitions - OS, Recovery, Primary. Another way is to convert the MBR disk to GPT.

1. Press Shift+F10 to bring up command prompt.
2. Run diskpart command. 
3. "list disk" to list disks.
4. "select disk 0" if disk 0 is the one you want to install Windows on.
5. "clean" to wipe the selected disk.
6. "convert GPT" to convert the selected disk.
7. "exit"

This time you should be able to install Windows successfully. Just be aware that during the restart, remember to remove the USB disk, so the laptop will boot from the hard disk.