People have confirmed that you can take the upgrade media, with or without anything installed on the hard drive and you can install "clean" Windows 7 and it will activate no problems.
System Manufacturer/Model Number Self-Built in July 2009 OS Windows 7 Ultimate x64 CPU Intel Q9550 2.83Ghz OC'd to 3.40Ghz Motherboard Gigabyte GA-EP45-UD3R rev. 1.1, F12 BIOS Memory 8GB G.Skill PI DDR2-800, 4-4-4-12 timings Graphics Card EVGA 1280MB Nvidia GeForce GTX570 Sound Card Realtek ALC899A 8 channel onboard audio Monitor(s) Displays 23" Acer x233H Screen Resolution 1920x1080
Keyboard ABS M1 Mechanical Mouse Logitech G9 Laser Mouse PSU Corsair 620HX modular Case Antec P182 Cooling stock Hard Drives Intel X25-M 80GB Gen 2 SSD
Western Digital 1TB Caviar Black, 32MB cache. WD1001FALS Internet Speed 15/2 cable modem Other Info Windows and Linux enthusiast. Logitech G35 Headset.
yeah, when selecting the drive you want to install on, click advanced options, then click the format button (I saw all of this in a video, somebody please correct me if I'm wrong), something like that.
System Manufacturer/Model Number Compaq Presario CQ60-215DX OS Windows 7 Home Premium CPU 2 AMD Athlon 64 X2 Graphics Card NVIDIA GeForce 8200M G graphics
Of course you can do a clean install. It is the license you are upgrating by buying an "upgrate version", NOT the c:\.
If you upgrate from XP, then all you _can_ do is a clean install, but if you are on Vista, and Vista and 7 are same language, then you can upgrade your system without a clean install (not recommended though)
OS Windows 7 Ultimate x64 CPU Intel E6850 3,0 running 3,6 Ghz Motherboard Gigabyte DS4 P35 Memory 2x2 and Gb Corsair PC6400 CAS5 - 4GB total Graphics Card Nvidia Geforce 260GTX Sound Card Creative X-Fi Fata1ty Gamer Extreme Monitor(s) Displays Samsung 2493hm Screen Resolution 1920*1200
Keyboard Logitech G15 (blue backlight) Mouse Logitech G5 laser PSU Zahlman 850HP Case Shg Cooling Evo 120 Hard Drives Intel X25-M SSD for system
2x 1Tb Samsung F1 as seperate discs Internet Speed 25/25 mbit Other Info 1 Samsung SATA dvd-burner
1 LiteOn SATA dvd-burner
System Manufacturer/Model Number Airbot 2.0 OS Windows 7 Ultimate x64 SP1 CPU Core i7 920 (D0) @ 4Ghz, *26c idle *65c full load on air Motherboard Asus P6X58D Premium - Sata 6Gb/s - USB 3.0 Memory 12GB DDR3 Corsair Dominator -CMD12GX3M6A1600C8 at 1600MHz Graphics Card EVGA GeForce GTX 480 -Aftermaket Accelero Xtreme Plus cooler Sound Card ASUS Xonar D2X Monitor(s) Displays 1 LG 24" Flatron W2453V-PF 1 Samsung 24" P2450H both 2ms RT Screen Resolution 1920x1080@60hz
Keyboard Logitech Wireless MK700 Mouse Logitech Wireless MK700 PSU Corsair HX1000W Case Cooler Master HAF 932 Cooling Case Fans *3 230mm, *1 140mm/CPU - *Tuniq Tower 120 Extreme Hard Drives 1 OCZ Vertex2 180GB SSD
1 TB Samsung Spinpoint F1 7200RPM 32MB cache
2 500GB WD Caviar Blacks 7200RPM 32MB cache (WD5001AALS)
Pioneer DVD Burner DVR-S18M Internet Speed DL 15 Mbps UL 0.98 Mbps Antivirus None Browser Firefox Nightly Other Info Processor-7.7 *RAM- 7.9 *Graphics-7.9 *Gaming Graphics- 7.9 *SSD- 7.8 W.E.I final score= 7.7
*Phone- Samsung Galaxy Nexus