If you are running a 64-bit host OS then by definition you have 64-bit hardware. The most likely problem is that you have not enabled, or your CPU does not support, virtualization support as explained here:
Installation Requirements
When you install Workstation, the installer performs checks to make
sure the host system has a processor that meets the following
requirements. You cannot install Workstation if the host system does
not meet these requirements.
- 64-bit x86 CPU
- LAHF/SAHF support in long mode
You can use CPU-Z or a similar utility to determine if the host system
CPU is 64-bit capable. CPU-Z shows EM64T (Intel) or AMD64 (AMD) if the
processor is 64-bit capable.
If you plan to install a 64-bit guest operating system in a virtual
machine, the host system must have one of the following processors.
Workstation will not allow you to install a 64-bit guest operating
system if the host system does not have one of these processors.
- AMD CPU that has segment-limit support in long mode.
- Intel CPU that has VT-x support. VT-x support must be enabled in the host system BIOS. The BIOS settings that must be enabled for VT-x
support vary depending on the system vendor. See VMware KB article
1003944 for information on how to determine if VT-x support is
enabled.
If you can see what CPU you have, you should be able to check if it does support VT-x and how to enable it in the BIOS.
I couldn't install it since it detects a 32 bit hardware at the startup.
<- that is your answer.