Remove temporary files,temporary Internet files:-
Disk Cleanup helps free up space on your hard drive. Disk Cleanup searches your drive, and then shows you temporary files, Internet cache files, and unnecessary program files that you can safely delete. You can direct Disk Cleanup to delete some or all of those files.
Remove memory dump files:-
Search for *.dmp and delete the files.
Defragment the hard disk drive:-
Disk Defragmenter consolidates fragmented files and folders on your computer's hard disk, so that each occupies a single, contiguous space on the volume. As a result, your system can gain access to your files and folders and save new ones more efficiently
Increase the paging file size:-
1.Click Start, click Run, and then type sysdm.cpl in the Open box.
2.Click the Advanced tab, and then click Settings under Performance.
3.Click the Advanced tab, and then click Change under Virtual memory.
4.Under Drive [Volume Label], click the drive that contains the paging file that you want to change.
5.Under Paging file size for selected drive, click Custom size.
6.In the Initial size (MB) box, enter a new initial paging file size. The size should be at least 1.5 times the amount of system RAM.
7.In the Maximum size box, enter the maximum paging file size. The size should be at least two times the size of the initial paging file size.
8.Click Set, and then click OK three times.
9.Click Start, and then click Turn Off Computer.
Boot in to Safe Mode and scan your system with latest versions of malware removal tools (like-Spybot,Search and Destroy,CWShredder as well as Adaware etc.)