HD shrinks when increase RAM

[Thinkthonk]

I have an X201, 120Gb SSD, Win 7 pro x64, 4Gb RAM. 6Gb RAM, Processor Intel(R) Core(TM) i5 CPU M 580 @ 2.67GHz, 2660 Mhz, 2 Core(s), 4 Logical Processor(s)

Have today increased RAM from 4 to 6 Gb. Ran a mem test - no problems. After restart notice that the HD now shows 56.2 Gb available and before RAM install it was close to 60 Gb. Why has adding RAM reduced the HD available space ? I've never had this happen before in any computer.

[RealBlackStuff]

The C:\pagefile.sys grew because of that.

[Thinkthonk]

I didn't want to reduce the pagefile size, so after a quick info search disabled hibernation and that restored the space. Thanks.