How much HD space should I give Windows 7?

[Smoochydies]

I have a TB which shows up as 931.3 GBs in the windows 7 setup.

I don't plan on using any other OS but will my computer be slow if I allocate the whole thing?

 

[sminlal]

If you really, REALLY want the best possible performance out of a single drive, then create a partition no larger than you absolutely need and don't put anything else on the same disk. For example, if you can get away with 100GB for the OS and you don't need to store any data on the disk (or are using a different disk for data), then partition the drive down to only 100GB.

The reason this helps performance is that it keeps all of the files close to the outer edge of the platters where the transfer rates are the highest. It also prevents the arm from having to move very far to access any file, which speeds up access time.