[siochi (OP)]

I think it can be done by making the operating system more efficient. Are there any other ways this could be achieved?

[CliffordK]

You will find a lot of notes on overclocking.

I suppose it all depends on your overall goal, and your current state of your computer.  Things like real-time antivirus programs can be very inefficient.  Never run two concurrent antivirus programs.

If you have a single program that you are wishing to run, then evaluate stripping out anything unnecessary to its operation.  Perhaps look at better caching.  Maybe a ram drive could help in certain situations.

If it is PC computing in general, then perhaps some of the same things apply, but it may also depend on how you use your computer.  I have a bad habit of getting 20+ windows open  [xx(]

One other thing to keep in mind.  32 bit operating systems have problems with more than 2 GB RAM.  If you have 4GB or more, you really need a 64 bit OS.

[assimilated]

You could change the performance settings and "adjust for best performance." That makes a big difference with windows 7 or vista but you will no longer get the "pretty" aero look.

I play computer games and have a separate login profile for playing which also has very few processes running in the background. By doing that it frees up a lot of memory and increases performance a great deal.

[AuToFiRE]

If you want to possibly kill your computer, you can overclock but i recommend using better cooling methods than the heatsink that came with the processor, or if you are looking just to make the computer run faster, use linux

[yor_on]

as Assimilated says.
Simple, and will give you a better 'speed'.
Otherwise, back up to XP pro, and do the same

Or Linux.

[Daerana]

upgrading your drivers would also help