Hey there. I have a XPS 420, purchased in 2008, Windows 7. The machine runs slowly, browser hangs up a lot, Shockwave crashes, lots of malware. I've tried to re image the computer - no change.
Now i'm considering completely wiping everything out and starting over with a Clean Install of Windows 7. Is there a document that would take me through all necessary steps?
If the system has never been reloaded, power on, press F8 a few times, and choose "Repair" and then "Recover" from the menu that appears. This will reload the factory image on the system.
Once that's done, you will likely want to to apply the Windows 7 post-SP1 rollup, or you'll be installing a few hundred updates through Windows update:
It might also be a good time to consider upgrading to Windows 10 while the offer of a free upgrade is still in place.
If this is what you mean by "reimage" -- you've already done it and the system is still slow -- run an extended hard drive diagnostic on the system (f12 at powerup). You may find there is something wrong with the hard drive - which, if original, is already well beyond its expected lifespan.
A newer drive will require INTEL RST F6 drivers. Most all drives larger than 120 gigs are advanced format. A dell Windows 7 SP1 DVD will install with the Sata Mode set to ATA instead of AHCI. This would then not require F6 Drivers to install. A Dell Windows 7 SP1 DVD will not ask for a COA key but rather will just install. In order to get a free windows 10 update you can start with windows 10 TH2 DVD and install without entering a key then change the key to what is on the COA either Home or Pro. This will work up to July 29th then never work again. Windows 10 will install in AHCI mode but will require INTEL RST of the correct version to be installed to get back the RST console and proper drivers.
At the moment you can use your Windows 7 Retail Key (this system should have shipped with Windows Vista OEM or Windows XP OEM) to Clean Install Windows 10 see here for details:
To Clean your Drive properly see here:
Windows 10 should have all the system drivers inbuilt or automatically obtain them from Windows Update.
Otherwise if your intent is to really stick with Windows 7 Retail see here:
Windows 7 system drivers are available here:
Note the system has a Legacy BIOS and not a UEFI BIOS.