Windows 7: RAM: 4GB installed and only 2.93 usable.

NONE of those options should be checked, have you been playing around with computer settings?:
Attachment 184385
Do both of your RAM match (are they the same RAM stick) or do you just have a single stick.

When did this problem start happening?

You have a 64bit opperating system, so this is weird. what are all the settings you've played with in windows thus far, and why?

Also, your video card may be sharing internal memory. Your motherboard needs a 48bit or 64bit chipset, and your BIOS must support 64bit memory mapping (and it may need to manually be enabled by you). Be very careful in the BIOS, as one false step and you'll be reloading your operating system all over again

I think you are using on-board graphics, so that is probably where the missing RAM is going to

The BIOS must support the memory remapping feature. The memory remapping feature allows for the segment of system memory that was previously overwritten by the Peripheral Component Interconnect (PCI) configuration space to be remapped above the 4 GB address line. This feature must be enabled in the BIOS configuration utility on the computer. View your computer product documentation for instructions that explain how to enable this feature. Many consumer-oriented computers may not support the memory remapping feature. No standard terminology is used in documentation or in BIOS configuration utilities for this feature. Therefore, you may have to read the descriptions of the various BIOS configuration settings that are available to determine whether any of the settings enable the memory remapping feature.

Did you do a clean install?

Is your current system specs out of date or something?

I found this thread for you, might pertain to your problem: Windows 7 64 bit RAM issue?

Chipset limitation. Full specs on that Acer laptop,

Acer Support: Extensa 5630Z Series Specifications

and the specs on the GL40 Express chipset in it,

Mobile Intel® GL40 Express Chipset

It only supports up to 4 GB. And why it is happening,

The system memory that is reported in the System Information dialog box in Windows Vista is less than you expect if 4 GB of RAM is installed

Without the above option in the bios 64 bit Windows will have the same memory limitations as 32 bit Windows.

So does this basically mean that i don't have the hardware to support 4gb RAM?

Or is it that it does support it but some of the memory has been syphoned off to the integrated video card and other resources ?

Either-or or both. Your integrated graphics are probably using some of the RAM. You could install more RAM and see if it helps, but up to you. Do you really need more RAM, since you really wont be using it much as your graphics are integrated anyway?

Unless you have 7 programs open at once and 11 tabs open in your browser, you shouldn't have any slowdowns.

32bit really isn't that bad of a choice in your situation, but I'm not sure it is that important that you reinstall or anything (oh, it isn't).