Restore points get erased automatically. If you want snapshots of your system, just image the drive after installing windows and again after installing your programs.
Just let windows create automatic restore points. It does a fine job on it's own. You may want to decrease the amount of disk space they can use though.
If you do a system restore to a time before you installed a program, it may not function properly as the registry will be restored to a point before you installed the program. In this case, you may have to reinstall the program.
Only use system restore when absolutely needed.