(1)RAM 384, maybe on-board graphics card used up 128MB
(2) HDD: 72GB no such capacity HDD ever produced 80gb/1.024/1.024/1.024=74.5GB, different way to quoting GB and gb, the rest of 2GB maybe in a hidden partition for storing recovery files
(3) CPU 2600+ or 2000+, you (they) may set wrong bus speed, FSB =133MHz for 2600, if set at 100Mhz, it will behave like a 2000+
By the way, how did you found those info.
Get a PC guru to check it or you if you decide to take any action, however it may be too late.