Desktop

No you will not be able to do this without rebooting.
Intel has a utility that can be downloaded
I currently use a utility program called SiSoft Sandra that will give you details about your computer that can be downloaded from net www.zdnet.com/download or www.sysopt.com/sandra

Ditto. The only way to find the cpu speed is to reboot and check it in the bio's . There are serval programs avaible that you can run in widows that will tell you. I use Norton system works.

Yeah most computers show that at start up. But some don't so use norton when in doubt

Im not sure about on the local machine without restarting, but you can go to Intel and download a small application called Intel Processor Frequency ID Utility. This will give you all the info of your processor: cache size, reported speed, expected,etc. To find it do a search
and in the field type

processor id

This will take you right to it. Hope this helps.

Here's the program that you need for finding detailed info. Great little program so you don't have to reboot or go into bios. http://www.cpuid.com/download/cpu-z-108a.zip