Upgrading Vista 32 bit to Windows 7 64 bit in Inspiron 1520

Vista OEM 32 bit came with my Inspiron 1520 in 2007. About a year later I upgraded it to Windows 7 32 bit even though I got both 32 and 64 bit upgrade CDs when I bought it.

I just changed the memory from 2 GB to 4 GB and I need to change the hard drive as well as the 160 GB has fairly ran out of space. I purchased a 750GB from Dell as they say it's the limit my system can manage.

I received 4 re-installation disks at the time of purchase and I would like to make sure I'll be doing the re-installation in the correct order once the new hard drive is in. Should I re-install in the following order?

1.  Applications: Dell Media Direct 3.3? It says on the CD to 'Use this media before you install your operating system.'

2. Windows Vista Home Premium (32 bit)

3. Drivers and Utilities? This has (a) Device drivers and (b) Diagnostics and utilities

4. Drivers and Utilities: Webcam Manager?

As I did a Performance and Tools check and see that my system is 64-bit capable, can I upgrade from Vista 32 bit with Windows 7 64 bit instead and would that require any major changes?

Right now I know that my printer and wifi works fine with 64 bit as I am currently running Win 8.1 64 bit as well and they all are working well together.

System processor is intel Duo CPU T5250 @ 1.50GHz