You can do it through the built in facility Bcdedit, which is a nightmare, or take the easy route. Download EasyBcd or Vistabootpro, (They are free) which both give you the opportunity to change the names, among other useful features.
Operating System Windows 7 All varieties (64Bit) Now Windows 8
Computer Type Self built
CPU Type and Speed AMD X4 2.8 Ghz
Motherboard Chipset Gigabyte MA74GMT
System Memory Type 4096 MB DDR-3 1333 Mhz
Video Card Type and Speed Radeon HD 5450 1024 MB PCI-E
Hard Drive 320 GB SATA
Anti-virus Software MSE
Computer Skill Level Self-Taught Expert
Favorite Game Pool/snooker Online.