Did I have 32 bit or 64 bit?

What would keep the 64-bit from loading on an empty or new PC? I'm still confused

If the CPU is only 32-bit the 32-bit version of an Operating System will be only one able to be installed. If the CPU is 64-bit either version of the Operating System can be installed.

It's clear. Insert the x64 DVD and see what happens. If it gives an error with a description "Attempting to boot from a 64-bit application,however not compatible in 32-bit mode.",it is x86. If it is x64,after installing,check in C: to see if there are two Program Files folders,Program Files and Program Files x86. If there are both,you have x64.If you only have the former,it is x86.

Of course,if you don't have 4 GB RAM or more,there's no point in installing 64-bit.

carwiz,the first CPU to support AMD64 was AMD Opteron,released in April 2003.
Not until Windows Server 2003 was released,was there an OS that supported x64.
Intel Itanium was really different.It supported the IA-64 architecture,which was not compatible with x86. Itanium dies,as Windows Server 2008 R2 is the last OS to support it. However,it was the first architecture to support EFI.

Too many "ifs and unknowns" for my limited knowledge/ability ... so i ask questions ...

Why was the HD replaced ?
What are the specs for the PC being worked on ?
What is the budget for the PC owner, can they afford $ (adding RAM, etc.) to the PC ?
What does the owner use the PC for ?

If it's just the "normal" browsing the web, email, etc., adding RAM or any $ cost may not be worth it.
If they do Video Conversions, CAD, Photoshop, etc., maybe hardware upgrades are the best recommendation.

If it's an OLD PC, upgrading hardware on an old PC may not be the best solution, at some point it's not worth the cost to continue using an OLD PC.

Thanks everyone for your replies. I learned a lot from them. The original issue was he could not log in using his admin password. Someone told him to use command prompt and reformat the hard drive.. Then his problems began. He could not reload 7. That is when he called me. I attached the drive to my PC and it would not even show up. I put in in another PC and tried to load 7 and it would not. I put a used drive that I keep around for troubleshooting in his laptop and 7 loaded fine. I plan on picking up a drive today and loading 7 for him. The laptop has 3G of RAM so I will let him make the decision on 32 or 64. He said it had 64 on it, but I wonder if he really knows. Anyway, I will let him decide and of course educate him on the difference and the need for more RAM should he choose 64. I will post back after the install to let everyone know the outcome.

Not sure why the drive died. In the words of the church lady on Saturday Night Live said "Maybe its SATAN!!!" Thought that might bring a chuckle.