Probably not well. While Vista is an older version of Windows, it is still made for a multicore processor. The best OS to run on that CPU and speed would likely be Windows 2000. Also, machines that are that slow likely don't have much memory.
The Xeon with EM64T and Pentium 4 with EM64T processors
Yes, the official CPU requirement for Windows 7 32-bit is simply a x86 CPU clocked at 1 Ghz or above. Any Intel Pentium 4 meets those technical specifications. About Windows 7 64-bit, it depends on model of Pentium 4 : first models don't support x86-64 instructions but the newer models fully support them. Nowadays, a lot of netbooks with single core Atom are shipped with Windows 7 despite the fact that power processing of these netbooks is significantly below most Pentium 4-based system (especially Pentium 4 with HyperThreading)
Socket 7 supported CPUs include: 2.5V - 3.5V Pentium 75-200 MHz and Pentium MMX 166-233 MHz, AMD K5 through K6, Cyrix 6x86 (and MX) P120 - P233.
recommended minimum CPU requirement for a windows server 2003 system running sus is 1 GHz Pentium III or higher processor; 3 GHz Pentium IV or higher recommended (dual processors recommended (for more than 10,000 clients).
Intel.
Yes, the official CPU requirement for Windows 7 32-bit is simply a x86 CPU clocked at 1 Ghz or above. Any Intel Pentium 4 meets those technical specifications. About Windows 7 64-bit, it depends on model of Pentium 4 : first models don't support x86-64 instructions but the newer models fully support them. Nowadays, a lot of netbooks with single core Atom are shipped with Windows 7 despite the fact that power processing of these netbooks is significantly below most Pentium 4-based system (especially Pentium 4 with HyperThreading)
Windows 7 32-bit is the highest version compatible with the Pentium III processor. : the official requirement about processor is "a x86 CPU clocked at 1 Ghz or above" and some models of Pentium III meet that technical specification. Please note that only the 32-bit version of Windows 7 can run on Pentium III. Moreover, it is recommended to have at least 1 GB of RAM for Windows 7 32-bit, which is a huge amount for a computer of this era.
Yes
Pentium Duo Quad, Pentium core duo, Pentium D, Xeon, Itanium, Pentium M, Pentium 4, Celeron, Pentium 3, Pentium 2, Pentium Pro, 486, 386, 286.
Pentium 4 with HT technology runs at the highest speed.
Yes, but it must be with one of the same type. EG, you can swap an Intel Pentium 3 1.5GHz with a Intel Pentium 3 2GHz, but not with an Intel Pentium 4 2GHz. Also, it must be the same socket type.