There isn't much to do for a system with those specifications that runs Windows 7 Basic on it. But i suggest a more advanced set of solutions that should give you a much deserved boost for your system.
You can switch off the Windows Aero theme and select a classic theme what will improve computer's performance by not using too much video RAM for other effects or transitions:
1. Click the Start button.
2. Right click the Computer button and select properties.
3. A new window will appear with basic information about your computer. Select Advanced System Settings on the left side panel.
4. The new window will contain 5 tabs, of which we will access the Advanced tab, an then in the Performance dialog, press the Settings button.
5. A new window will appear with the Visual Effects tab select. From the check the Adjust for best performance radio button and then click Apply, wait for the settings to finish loading, and then click OK.
Another trick that you can do is by turning off unnecessary services:
1. Type msconfig in the Start Menu search box.
2. A new window will appear with 5 tabs. Select he Startup tab.
3. A list of processes and services will appear. These start once you boot up windows. You can uncheck whatever you think it's unnecessary and then click Apply, and reboot.
These are the safest methods to boost your performance on these specifications.
The reason why the performance of your computer is very slow is because of the amount of physical RAM installed. I guess you need to upgrade the memory of your computer. Your computer is running on the smallest possible amount of memory supported by Microsoft Windows 7.
Windows 7 requires at least 1 GHz or faster 32-bit or 64-bit processor, 1 GB RAM for 32-bit and 2 GB RAM for 64-bit, 16 GB hard drive space for 32-bit and 20 GB for 64-bit, and Microsoft DirectX 9-compatible video card with WDDM 1.0 driver or higher. The only way to speed up things on your computer is to add more RAM.
Even if you regularly defrag your hard drive to have an optimal performance on data access that is still not enough because of the amount of memory. Since you only have 1 GB RAM, the computer has to transfer most of the data to the page file or the virtual memory of the operating system during processing and that’s the main reason of the slowness.
Processing is a lot faster when data is located and processed on the physical RAM rather than on the page file which is located on the hard drive. There’s a big difference with the speed between a hard drive and a memory module or memory card.