Reduce Windows 7 memory footprint

I have a netbook with 1 GB of RAM and Windows 7 Starter and it still eats lots of memory without any background program despite reading all tutorials on the internet (kill any non crucial background program and services, using classic theme, disabled visual effects, cleaning registry and junk files, etc)
This makes the hard drive light stay on almost constantly while the RAM is 99% used.

If anyone knows another way to improve RAM memory please reply :)

Post a screenshot of Task Manager - Performance tab. This will give a better picture of what is happening.
On a system with memory problems disabling the pagefile is the worst thing you can do. This would make things worse, if it would run at all.

Windows 7 is not going to run well with 1 GB RAM.

I have a netbook with 1 GB of RAM

It's very possible to get w7 to use less mem, shaving off startup programs and non-crucial services (see attachment, HP 6735b w7 32bit ultimate, less than 600MB with ff + more stuff running). But you may have some of the 1GB gone to start with > hardware reserved... so getting yourself a GB more of ram is recommended in all circumstances.
Post a resource monitor shot of your memory usage.

What programs do you generally run? You will need more RAM too.

Running Windows 7 with 1 GB RAM is a problem but it does meet the minimum requirements. With a workload within it's means it should run reasonably well. Ultimately it is the system memory manager that controls memory usage and it will try very hard to maintain a reasonable amount of available memory. Having 99% memory usage is a good indicator that something is wrong. Solving problems starts with information and at present there is very little. A screenshot of Task Manager - Performance tab, will provide much of that.