Ummm well this is a weird sort of question to be put on a Computer Hardware forum but...
Wear a dustmask because most likely an old computer that hasnt been used wil gather dust. Even if you use it everyday it gathers alot of dust. like the computer I got now. the chassis fan had a quarry on it. alot of dust so be careful about dust if you have alergys.
Intel Core 2 Duo E6600 @ 3400Mhz
BFG 8800GTX OC
Samsung 400 GB Sata II
Corsair XMS2 2GB DDR2 800 5-5-5-12
Zalman CNPS-9700 LED
Antec Nine Hundred
Hp W2207 22" Widescreen Monitor
Windows Vista Home Premium
Silverstone ST60F 600W PSU
Razer Copperhead Tempest Blue Gaming Mouse