Upgrading From Win 7 32bit To 64 Bit Problems

I have a

Toshiba Satellite L Series L675D-S7022 LAPTOP
AMD Athlon 2 P340 Dual-Core Processor 2.20 GHz
4GB DDR3-1600 Laptop SODIMM DDR3 Memory RAM Module
32 bit WINDOWS 7 ULTIMATE SP1

that I am trying to upgrade to 64 bit but I cannot get it to upgrade... from startup with CD or USB. This machine came originally with WIN7 HOME 64 bit but was upgraded to WIN 7 Ultimate 32 bit. How can I get it to upgrade to WIN 7 ULTIMATE 64 BIT? I have the ISO from Windows website. I would prefer not to delete data on HDD if possible.
Thank you for your time and effort in this matter.

 

You cannot upgrade Windows 32-bit to 64-bit. You have to do a full re-install.

Backup your personal files. and install Windows 64-bit.

 

It originally came with 64 bit win 7 home but it crashed and they put win 7 ultimate 32 bit. I have heard others say that you could install 64 bit ultimate keeping your files intact, but I haven't been able to get it to do so. So, I guess you must be right. Thank you for your confirmation on this.

 

You're welcome.