The 32/64 bit is determined by the CPU not the operating system.
On the Windows operating system, go to the Start menu > All Programs. Open the Accessories folder, then the System Tools folder. In the System Tools folder, select the System Information option.
On the right side of System Information, look for the System Type option under the Item column. The associated value, in the Value column, will tell you which type of CPU the computer has in it. If the System Type value includes “x86” in it, the CPU is 32-bit. If the System Type value includes “x64” in it, the CPU is 64-bit.
Another thing to consider, if it’s old, check out what the speed of the processor in the laptop is now. It may not eve meet the Windows 10 minimum requirements.