I guess you don't have a Win7 Home Premium install disk. Actually you can legally install a fresh copy of Win 7 Home Basic in your Laptop without the bloatwares from manufacturer. In a nutshell you need to backup your activation data, Clean install OS and then restore your activation. Here is the complete steps :
1) Backup OEM Serial Key and Certificate.
To do this download "Advanced Token Manager" from http://forums.mydigitallife.info/threads/27341-Advanced-Tokens-Manager-The-Activation-Backup-Solution
Run the tool and backup your activation data.
2) Perform a clean install of Win 7 with Win 7 Home Premium ISO downloaded from Digital river. You can use USB installation if you don't have a DVD drive. For step by step instructions please visit http://www.howtogeek.com/forum/topic/how-to-do-a-clean-install-of-windows-7-8
3) After Setup finishes re run tokens manager and restore activation data.
I highly recommend everyone to backup their activation data using tokens manager as MS imposes a number limit on activations. It might come handy when re installing legal copy of Windows. Since backup token's won't work in other machines this method can't be used for piracy.
There is also another tool called ABR which is specially used to aid reinstalling OEM Win 7 machines those who comes without install CD. It can backup and restore activation data like token manager.
Note : Neither of these tools can't be used for illegal activation. You should use the exact same machine and exact same edition of Win 7 to successfully restore an activation backup.
Edited by Anshad Edavana, 15 April 2013 - 09:16 AM.