In case you want to restore the computer to the factory installed state, follow the steps given below:
Restart the system and press the F8 key at the Dell logo every 2 seconds. On the ‘Advanced boot Options’ use down arrow key and select ‘Repair computer’.
The software is now installed as it was when the computer was first received.
Also go through this link for further assistance:
Revert for further queries.
The diagnostics indicated a dead HDD- it's tossed out.
It's been replaced with a drive from a Toshiba laptop - it had Windows7 Home Premium, and loads fine.
Now I have issues with drivers, network connectivity, Windows legitimacy and so on.
If we use your F8 approach, will the different HDD cause issues? No problem if formatting the drive is required.
It won't work, the F8 restore to factory settings relies on a hidden hard drive partition on the original drive.
You need a Windows Reinstallation DVD. I assume Windows 7 Home Premium also. Unfortunately as you don't reside in the US there is no online request form for the reinstallation DVD and you have to phone technical support which leads to varying results... see this poll here for more details:
I had a reinstallation guide up which explained the reinstallation process in great detail but I removed it until the issues for requesting media are resolved for non-US customers.