|Please post your system specs, at least the make/model/speed of the CPU & amount of RAM. If you have an OEM system (Acer, Dell HP, etc), post the make/model. It's difficult to help when we have no idea what you have. Could it be it's just an old, slow machine with a weak CPU with too little RAM & a HDD that's almost full?|
When's the last time you scanned for viruses & malware? Do you regularly dump the accumulated internet garbage files? Have you managed your startup apps so that you don't have a bunch of useless crap running in the background? Do you defrag regularly?
"Is it alright to delete the virtual memory on drive C ?"
Delete it? Do you understand what virtual memory is & how it works? Just leave it alone. If you've already altered the setting, change it back - let Windows handle it.