Unfortunately, my knowledge is very limited about these matters, but I'm wanting to do a clean installation of Windows 7 Ultimate 64-bit. I've been reading and jumping to links trying to grasp it, but due to obstacles progress has been slow, and today (very shortly) a friend is bringing his laptop by so I can burn the bootable OS system to a thumb drive. I'll explain my situation, and then can someone recommend what files I need (and any other advise)? Thanks for any help here. I bought a used laptop, a HP Compaq Presario F572US. It has Windows 7 Ultimate 64-bit installed, but from what I gather at HP's website, it originally shipped with Vista (as the sticker on the bottom indicates). This particular model was not among those available for upgrades to Win7, so I don't know who did the upgrade or where the file came from. I don't know if it's related to me changing information on the device or not (such as the computer domain name), but I had been getting notices from Windows that it appeared to be not authentic and I should validate it. I suspect I had an ongoing malware problem (numerous processes, services and drivers seemingly linked to ports and networked manipulations, hidden and locked files, changes to my security and antivirus software, etc) but no virus' were found in the last few months (Malwarebytes' Anti-Malware, Webroot, Avast, and ESET). A handful had been found and removed in the month or so prior t that, though; I've had the computer about three months. Suspecting rootkit activity, I ran Kapersky's TDSS Killer which warned about several files, some of which were locked. Long-story-short, when Quarantine seemed to fail I tried Delete on numerous files without properly investigating them via Google or a forum. My laptop now will not start, but it appears my drives and data are there (though inaccessible). It shows three volumes (described from my memory; sizes approximate): 0 - E - CD/DVD - 0/0 bytes - "no media present" 1 - C partition - 30/100 MB - (I think a Windows 7 installation file is located here, among other OS files) 2 - D partition - 46/74 GB - (This seems to correspond to what I used to see in C:\ with installed OS and data) I have not recovered my data yet, and would appreciate suggestions on whether I should (I'm worried about transferring malware into another device, including my friend's laptop). Nothing is absolutely vital, though there are files I'd like to keep (mainly programs I've downloaded, serials to my programs, and less-so, some pictures and various other data. I have only owned this laptop for about 3 months and have not put a lot onto it). I can see at least some of my data through the Recovery Panel (Advanced), by way of it's attempt to locate a driver for backup media (which I don't have). It's only allowing browsing for "setup" files, so I can't actually retrieve or launch anything (it reports no associated driver is found). I can Right-Click/Properties/Open With and was able to copy and then past data into a Command Prompt window. I don't have the original installation disk (for Windows 7 or Vista), nor repair disks and such. Can, and should, one be made with that Win7 setup on C:\ or from the installed system files (on D:\ I assume)? I also don't have BartPE or WinPE, because I've been unable to burn a bootable disk file without my computer (I'm writing this on a library computer which prevents me from running .EXE files). I can access BIOS (Phoenix; which I learned at HP.com is in need of an update). I downloaded Hiren's Boot CD but due to an apparently non-functioning CD/DVD drive, it doesn't boot up. I'm going to use an 8GB USB thumb drive to load Win7 again (assuming I shouldn't use the Win7 setup I see in C:\). Through the Recovery Panel, I can select to open a Command Prompt window. The window opens in "X:\windows\system32". SFC /Scannow doesn't run, but reports another instance is pending (or something similar). I learned the disk information via Diskpart / List Vol, though this is the first time I've used Command Prompt and it's quite unfamiliar. So, that's my situation. Here's my (ever-changing) thinking as of now: Though I want my data, I'm wanting a clean, fresh start without malware, and don't want to infect my friend's laptop. I don't have another computer to master/slave the drive directly. Though I seem to have Win7 setup on my disk, I wonder if it might not be clean. A reason I've not done a repair is that I'm wanting a fresh, clean system to begin with (along with my inability to burn a bootable disk, until today via my friend's computer, and the failure of my CD/DVD drive to boot up Hiren's Boot CD). I see there are three versions of Win7 Ultimate 64-bit, among them two with letters in the link name (one is "N"; forgot the other). Which do I need? OEM or Retail? Daz's program or another method to register it? Should I update that Phoenix BIOS first, or is that done with Daz's program? What files go on the USB thumb drive along with the OS setup, and which should be on a separate thumb drive? Should I download via a torrent or a direct link ("River"-something, at Microsoft's site, or elsewhere?) Do I need to have new drivers already downloaded, and from where (HP? Microsoft?) Or, are what is needed with the OS setup? I do know that HP reports since my laptop was not one they assigned for updating to Win7 from Vista, they don't have the appropriate file set, but I think I saw links to some in an HP forum. Sorry so long, but I'm out of time and the more answers I find the more questions arise, and I need to at least burn the OS installation files to my USB drive today (very soon). Which one, from where, with what tools and along with what else? Thank you very much.