Also you want to hear on xmas that your thoughts will come true.....sorry, no way!
The max you will be able to upgrade to is a 266 MHz (consult motherboard manual).
Pentium II and III have a different structure and architecture of data processing.
To upgrade to a "clean" P II or III you need to change the board.
There is, however, a solution for older motherboards available, even a 486 can be upgraded to P II status and as far as I know it will be a 333 MHz celeron type processor.
You can accomplish this with a standard PCI (also as ISA available) add-on card with the new CPU fitted on it.
Upgrade is done in minutes and, surprise - surprise, it works.
Please remember what I said before, it is not a clean upgrade, I did not hear about problems with software etc. but, as it is always with "backdoor" solutions, there is also no gurantee of all programs running without trouble.
Good luck