That info is added by the manufacturer. Branded install media will add it but regular off of the shelf standard Microsoft disks won't. This is a reg file I use to add that info to my desktop PC.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\OEMInformation]
"Manufacturer"="Asus"
"Model"="M2N68-AM SE2"
"Logo"="C:\\Windows\\System32\\oemlogo.bmp"
One option is to open regedit in Windows 7 and export that key, then import it into Windows 8. You'll have to find the logo and copy it to the same folder location in Windows 8. There may be a lot more info in that key than what is shown above. Once you export that key you can edit out what you don't want transferred to Windows 8. There are utilities to add the OEM info for you, just Google it.
Yah just google a nice HP logo from the net, it has to be converted to BMP for it to work. Move it into the folder specified. Then add the reg entries.
Asus M2N-MX SE Plus § DualCore AMD Athlon 64 X2, 2300 MHz (11.5 x 200) 4400+ § Corsair Value Select
CPU
AMD 4400+/4200+
Motherboard
Asus M2N-MX SE Plus/Asus A8M2N-LA (NodusM)
Memory
2 GB/3GB
Graphics Card(s)
GeForce 8400 GS/GeForce 210
Sound Card
nVIDIA GT218 - High Definition Audio Controller
Monitor(s) Displays
Hitachi 40" LCD HDTV
Screen Resolution
"1842 x 1036"
Hard Drives
WDC WD50 00AAKS-007AA SCSI Disk Device
ST1000DL 002-9TT153 SCSI Disk Device
WDC WD3200AAJB-00J3A0 ATA Device
WDC WD32 WD-WCAPZ2942630 USB Device
WD My Book 1140 USB Device
PSU
Works 550w
Case
MSI "M-Box"
Cooling
Water Cooled
Keyboard
Dell Keyboard
Mouse
Microsoft Intellimouse
Internet Speed
Cable Medium Speed
Browser
Chrome/IE 10
Antivirus
Eset NOD32 6.x/Win Defend
Other Info
Recently lost my Windows 8 on my main PC, had to go back to Windows 7.