I have just purchased and installed Windows 7 (Home) with the intention of upgrading to W 10 via the Microsoft's Updates. The trouble is my Disc came with SP 1 only installed and there are literally hundreds of security and other updates needing to be installed which will take ages to complete. My question is :- Do I have to install all prior updates in order to accept the offer or can I simply install KB3035583 - KB3021917 - KB 2952664 which appear to be those containing the W 10 offer? 
My Computer
- Computer type
- PC/Desktop
- Computer Manufacturer/Model Number
- Custom Build
- OS
- Windows 7 Ultimate x 32 bit
- CPU
- Intel core 2 6600 @ 2.40 ghz
- Graphics Card(s)
- Nvidia GF 9600 GSO 512mb
- Monitor(s) Displays
- n/a
- Internet Speed
- 100mb
- Antivirus
- Avast
- Browser
- Internet Explorer