Removed programs but hardrive space unchanged

Hello,

I recently got an old laptop. I unistalled all the programs I wasnt going to use to free up the limited hardrive space (20gb). I uninstalled a 4gb (or so) adobe program. after uninstalling that program i checked to see how much space i had freed up.. but the free/used memory ratio on the hardrive was unchanged (from what it had been prior to removing the program). i went back to 'add or remove programs' and the adobe program was gone.. i've actually had this problem happen on other computers, but they had soo much hd memory that i wasnt particularly worried about rectifying the issue.

So anybody know what this is about and/or how to recovery the memory?

hopefully this is a proper forum to post this - sorry if it isnt