I am dual booting my system with Ubuntu 12.04 and Windows 7. I have created the special swap partition for Ubuntu while installing (as recommended).
Can Windows use this swap area/partition--as its own swap/page file--when I boot from Windows?
It's possible, but probably only as an experiment:
Alternative (still not recommended) option:
You can create a swap file by following this guide on the NTFS partition, provided the NTFS partition is large enough for both swap files.
However this alternative is not recommended because:
The short answer is: No, it cannot.
Windows does not recognize Linux partitions, although the opposite is possible (linux recongnizes windows partitions).
I haven't tried it myself but you can mount a swap partition with swapfs. You can then, in theory, place your pagefile there (there's some good reasons not to, such as minidumps, but its an option).
It works great.
Whats needed? Just follow the instruction in the SwapFs-3.0 file.
Also you could find some helpful stuff at How To use Linux Swap Partition as Windows Swap file on Ubuntuforums.org.
At first I tried to format swap space into NTFS but turned out that Linux lost ability to recognize it as an own created.
Then I reformatted it back to classical Linux swap.
Next I changed back fstab. Was:
Deactivated that and put instead:
If I remember well, after I booted into Windows it didn't recognized it as RAW or if I could have formatted it as FAT32.
And everything started working.
But a problem appear. Namely my Vista 'attached' an additional letter, thus at last had two drivers but in fact linked with the same partition 'e:\' and established by me as 's:\'.
Fortunately it was enough to get to the registry to place recommended in *.reg file, from 'SwapFs-3.0'. Turned out that the extra additional record 'e:\' should be removed from registry.
Right now enjoying inter-system swap space without problems. Recovered 3.2 GB space.
I would like to mention that using Linux just 4 three months and be able to do such complicated operations, thus you could do this without any enormous effort.