Can't increase memory allocation

Hi,

I'm trying but failing to increase memory on Parallels 3 on my MacbookPro from 512mb to 1440mb or more. Got 4GB hardwired RAM.

I get error messages that memory allocation failed, to restart and try again; to go to preferences and select "enable virtual memory prealocation."

It is checked and I'm doing it via preferences.

No matter what number I put in, I get another message that says to reduce it by 100mb, that it exceeds the limit, etc.

I'm in an endless loop here. How do I get off this merry-go-round and get the memory to increase???

Any help is appreciated.

 

It finally started up at 312MB.

Now, how do I carefully take it up to 1440 or even 1560 as I had intended?

Thanks.

 

In spite of this disable memory prealocation , and set to manual Adjust memory limit,
Please check that there is a space on Mac Drive at least 1 gb+ VM memory

 

Increasing memory

I have tried to increase the memory via preferences. With the preallocation checked OFF, I try to increase it manually but it wont let me go any more than 704mb? I have plenty of room on my computer but for some reason it wont let me increase this any ore. As a result, I cant do anything on parallels because it keeps telling me Im out of memory. Any solutions?