I have 2 other recommendations due to the age of your system before considering hardware changes.
Disk Cleanup and Disk Defrag.
Click Start orb, in the search box type cleanmgr.
At the top of the list Rt. click cleanmgr.exe and click Run as administrator.
The program will initialize and in the disk cleanup window you choose by
ticking the items to clean.
Then click the more options tab, and click the Clean up button under the
System Restore and Shadow Copies section. Click Delete on the confirmation window.
When that portion has completed (may take a few minutes) click the Ok button,
again confirm your intentions by clicking the Delete Files button and wait for completion.
Click Start orb, in the search box type defrag.
At the top of the list Rt. click Disk Defragmenter and click Run as administrator.
When the window opens First Analyze the OS Drive (usually C) by clicking Analyze Disk then Defragment Disk
Normally there are 10 stages to defragmentation so take a well deserved break.
Post back your thoughts/comments please!