Computer Not Booting?

[JDMJ2006]

Hey, i bought this old Pentium 2 off my friend.. its 333mhz and i just bought it for my mom to screw around on and i went to boot it up and it said i had 164 megs of ram .. which was right (2 64 meg sticks, 1 32 meg stick) then i rebooted and it said 132 megs then i rebooted again and it said 64 megs then i tried once again and it just my hard drive was running .. my cpu fan would spin for about 1 1/2 seconds and stop .. then nothing would happen, but the hard drive was spinning, any clue at all what it is?.. Buddy i bought it off said he thought it might be the CMOS battery but he has no clue .. reply or email me scents_of_your_insides@hotmail.com .. put "Computer Help" for subject so i dont think its just junk mail THX guys.