You cannot change or remove the partition that Windows is using
Unless you decide to use a bootable disc ( Windows CD ) and remove the partition or format it; which will remove Windows fully.
Some computer users have multiple partitions on one Hard Drive
ie C drive; D drive; E drive; so forth
Users usually have this set up as follows
C drive: Windows operating system and program files
D drive: Data (Music; pictures...) and other user data
E drive: Full install programs (entire of office CD; entire of Windows CD ...)
Therefore, it is possible to format partitions D or E drives (or further) But not C
There are different
formats too (just to make it more confusing)
Fat 32; NTFS; Fat64 and more - but these three are the most common for Windows harddrives
Usually in Windows Xp/Vista NTFS format is the most common, but newer computers are now using 64Bit which is faster. (But the motherboard and software installed must suit it.
Partitions
Are the ways in which the disk is divided up.
ie you can have 1 partition for NTFS format across the entire computer - the norm!
or
You can have 2 partitions with 2 NTFS formats for making a C and D drive (se above)
Actually you can have 128 partitions but practically 4 primary (main operating system) and unlimited logical drives.
Yes there's also a partitioning preference (Primary; Extended; Logical)
Actually the information on this is very extensive, it may be better to ask a specific question on Google.
ie Try typing in "How do I partition my Windows Xp hard drive" (without quotes)
As this information can be quite huge (to say the least) You may just want to be more specific.
Here's a good start page:
http://support.microsoft.com/kb/313348