If your computer is frozen it is mostly likely just the program you are using. To end an unresponsive program you must bring up the task manager by clicking ctrl-alt-delete then select task manager. In the task manager under the processes/programs tab find the program that in unresponsive, select it and click end task. If the entire computer is frozen you will need to force it to turn off by holding down the power button.
There are many hardware and software ways to make your computer faster. Hardware fixes would be increasing the ram, upgrading the processor or the hard drive. Software fixes can include defragmenting the hard drive, cleaning out the hard drive of excess files and by fixing registry errors. Fixing the registry and deleting excess temporary files and such can be done using a program called CCleaner; which is a free program to download and will significantly help your computer run more efficiently. You computer has a built in defragmentation program which can be found by searching defragmentation, then run the program.
The blue screen is nicknamed “The Blue Screen of Death.” However, it does not mean it is the end for your computer. There are many things that could be the problem, corrupted drives, burnt out chips, or operating problems. I would suggest to try to re-install the operating system, which can be done by booting your computer in safe mood. You will likely have to look up how to do this.