Swap hdd from x32 to x64 dual boot

So my laptop gave up and i bought the same one with a x32 version of win7 on it.
My old lap to p had a x64 version of win 7 with ubuntu12 (dual boot)
I'm planning on swapping out the hdd.
Anything I should be aware of before doing this ?
Laptop the same except no bluray player.

Do you mean you plan to swap the old laptop's HD to the new one? It may start up and it may not. If not you can try Paragon Virtualization Manager or before moving from old hardware SysPrep to move HD to another computer.

If you want 64 bit on the new hardware and it has at least 4gb RAM then you can also Clean Reinstall - Factory OEM Windows 7

right, old laptop hdd to new laptop. new laptop has x32, old laptop had x64.
would it help if i installed a 64 bit version on the new laptop then added the old hdd?
i do have 4gb. i cant do anything the old hdd because old laptop mobo died.

The old HD may start up, changing out all drivers which presents quite a show springing up from the System Tray which you need to monitor closely to do the requested restarts

If not you can clean install 64 bit using the licensed version ISO provided in tutorial, plug in the second HD after install to access it's data or install the Paragon app to adjust the second HD since the newest version doesn't seem to have a boot disk but adjusts a target Win7 from inside another OS. Then reboot and try to trigger the old HD to boot.

If you end up only using the old HD for data or storage you can move the data to another partiiton to correctly delete the old OS partition in Disk Mgmt

Good. Then if performance is good you can mark the thread Solved at top.