The first thing that comes to mind is that the hard drive may be fragmented and/or cluttered with junk files. It could also be unnecessary programs running in the background.

• Try running the disk defragmenter and see if that alone makes a difference. When my old XP machine (which had 98 even before that) would start to lag like that, that was usually the reason why.

• Run msconfig.exe and see if you have any unnecessary programs starting up with the machine.

• Open services.msc and see if you have any services set to Automatic that don't need to start up with the machine. Most can be set to Manual so that they don't start with the machine, but can still run when needed. Disabling is another option if you don't want a particular service to run at all. You can probably also use Automatic (Delayed Start) if you want something to start automatically, but you don't need it to start immediately with the machine; this should speed up startup time.

• Install either CCleaner or Advanced SystemCare to get rid of any junk files. If your computer is too slow to even do that, the built-in disk cleaner would still be a step in the right direction.

These won't make your computer lightning fast, but it should at least make it usable.