![Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops](https://4sysops.com/wp-content/uploads/2008/04/3gb.png)
Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops
![Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops](https://4sysops.com/wp-content/uploads/2008/04/4gb.png)
Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops
I have 4GB RAM installed in my computer but it says that only 2.45 GB is usable. I want to use whole of 4GB of RAM. How can I do it? - Quora
![RAM Recognition: 2008 Optiplex recognizes 3.25gb RAM with 4gb DDR2 installed, cool. Hope was 6gb DDR3 would be read as 4gb in a 2011 Lenovo Thinkcentre with x2 3gb DDR3 sicks, but RAM Recognition: 2008 Optiplex recognizes 3.25gb RAM with 4gb DDR2 installed, cool. Hope was 6gb DDR3 would be read as 4gb in a 2011 Lenovo Thinkcentre with x2 3gb DDR3 sicks, but](https://preview.redd.it/hq59ipfv7oq61.jpg?width=640&crop=smart&auto=webp&s=b1b0c42a04ab78782b6c881b1cd32bedef103ea5)
RAM Recognition: 2008 Optiplex recognizes 3.25gb RAM with 4gb DDR2 installed, cool. Hope was 6gb DDR3 would be read as 4gb in a 2011 Lenovo Thinkcentre with x2 3gb DDR3 sicks, but
![Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops Why Windows Vista only sees 3GB memory in a PC with 4GB RAM and how Vista SP1 fools its users – 4sysops](https://4sysops.com/wp-content/uploads/2008/04/4gb-msinfo32.png)