To tell ya he truth, If I had a 400 GB C:\ partition, I'd immediately be looking to reduce it to something more efficient for performance and maintenance reasons. Remember that your HD is fastest (about twice as fast) at the outer edge than it is at the inner edge. That's cause more real estate pass under the head in one revolution at the outer edge than at the inner.
So installing windows and then letting it decide how fast your machine is gonna be as it, over time keeps moving ya page file further and further towards that inner circle is unwise. For faster performance, improved backup and maintenance and ease if restores, consider the following:
1. Even with Windows bloat you can easily keep ya C:\partition down to 16 GB ....8 if you are fastidious.
2. With 16 GB allocated for C:\ you can then create a D:\partition for one sole purpose .... windows memory swapping and temp files. This is where your HD heads are gonna spend most of their time. No matter how much memory you have Windows is gonna swap stuff out. Programs and games will force writes to the page file even when oodles of physical memory is available. If ya wanna confirm for yaself, open task manager, go to processes tab, hit View / select columns and make sure Memory Usage and Virtual Memory Size boxes are checked. Right now, I have 1.2 Gigs of free physical memory and yet still have almost 400 MB paged out to disk. Taht's 400 MB of stuff that is being continually swapped between HD and memory.....you wnat that happening at full speed (outer edge) , 3/4 speed (middle) or 1/2 speed (inside edge).
So create a FAT32 D Partition of 8 gigs or so. Yes, FAT32 because NTFS has an overhead associated with it and you don't need "file protection" on files that get deleted or wiped at every reboot anyway. And yes I have benchmarked both FAT32 and NTFS Swap fiel partitions and it is faster.
3. Then go into Control Panel / System / Advanced / Performance / Settings / Advanced / Virtual Memory / Change and:
Set C to No Paging File (you lose dump file access but I don't know anyone who has ever looked at one after a crash and said "Oh cool, I can recover this"
Set D Minimum and Maximum to 2 x the amount of RAM you have. (you like a better number, use it.)
Reboot and then create a Folder called "Temp" on your D partition. Go into Control Panel / System / Advanced / Environment variables and select TEMP in the top window then hit Edit and change the value to D:\Temp...then select TMP in the window and change the value to D:\Temp. Now all the files your computer, programs and games will use most often are locked into being placed right at the outer edge of your hard drive giving your machine a distinct speed advantage over time. Otherwise, a year or so down the road when you have 200 Gigs of stuff on there, the paging file and temp files will have moved to the middle of your HD where they will be written and read at only 75% of the speed that they will on that D partition.
4. Then go with the rest of the drives as you see fit. I'd change the drive letter of your optical drive to Z to keep it the heck outta the way. Doing this saves headaches later if you add another HD or more partitions.
5. Next , depending on your usage, I'd go with E:\ being reserved for Games. Pick a size you deem appropriate. After all what do you need loading faster, your fragfest of game or pictures of granny and aunt tillie from last year's thanksgiving ? Of course if programs take precedence over games, then do programs 1st.
F:\ would then be for programs
G:\ say for data
H:\ say for backups and / or an alternate install of XP.
Peeps generally care a lot less how long it takes to load a data file and backups ...whatever you use to restore is a lot slower than ya HD.
Of course after D, what you set aside and how you allocate it is very personal. Again all but the page / temp file partition should be NTFS.
6. There's several other advantage. Ever screw up Windows....what's easier / faster to restore from your backup media....a 16 GB or 400 GB partition ?
7. And ya know that interminable wait when ya crash and the system does chkdsk on the next reboot and you wait while it chugs thru 400 GB...well most of the time, that chkdsk is only gonna run on the D partition and waiting for 8 GB is way way better than 400.
8. The breakout makes it easier to backup ya stuff. data partitions can be done daily or weekly.....programs monthly or quarterly even.
9. Daily Virus and malware scans can be limited to places where the stuff resides (C:\) .....do the rest of the stuff on a weekly schedule.
10. When ya HD gets "dinged" say when ya 18 pound bust of Darth Vader falls from is shelf on top of ya puter, ya most important stuff...the data....is located far away from the "park" position of ya heads. Windows can be replaced....often lost data can't be replaced.
11. Wanna clear out all ya old and useless files.....delete everything on D:\ .... that was easy.
12. Now ya can start thinking of putting that D:\Partition as the 1st partition on a second HD
. Though this isn't as good ideas ya might think if ya got an old HD lying around . Likelihood is that your new HD at the inner edge is faster than the old one at its outer edge. Still heads can't be at two places at once so it's a consideration.
I typically take a bare metal box and don't even load windows till after I have used Partition Magic to make all my partitions. Alternately, like when ordering a laptop, I have the vendor install windows on a 16GB partition and leave the rest unformatted. I then use disk manager to make D thru whatever.
The HD is the slowest part of your system. Everything you do on it is constrained by the weakest link in the speed train and that is ya HD. So best to make it work for you as best you can. So, if I were you, I'd be grabbing a copy if Acronis Disk Director or .... BootIt NG has a 30 day free trial period....and optimizing my HD work for me.
http://www.terabyteunlimited.com/bootitng.html