Upgrading Inspiron 9400

I have an Inspiron 9400 with 60 GB hdd & Windows XP. I plan to upgrade the hdd to 320 GB, & install Windows 7, and eventually Windows 10.  I was assured by Dell tech support that my Inspiron will only work with Windows XP or Vista. I have already run Linux Mint 32-bit Rebecca from the DVD with no apparent problems. My question is, can I actually install Win 7, or must I switch to Linux? Windows XP is getting worse & worse! I have considered installing Win 7 on a bootable usb hdd to test this out.