laptop repair or upgrade? No option to buy a laptop.

Keep in mind the 100% disk use is a common problem. At the shop it's better than 99% of the time some failing HDD. We REPLACE that drive, most often with a SSD and if we are lucky the old drive content is cloned to the new SSD and it boots right up and goes home.

Be aware we see a lot of people attempt to fix this with software or a clean install of the OS which seems to be the way people learn about this issue. Again, well and often discussed on the web and your story is repeating the past. I'll stop here and write this can be a cheap thing to fix. If that is a HDD then the usual 500GB SSD (Western Digital 500GB WD Blue 3D NAND Internal PC SSD) runs about 55 dollars.

You need to do a few things to keep it working as it was originally made.

Windows Messes up Hard Drives by just running and unless you defrag it constantly it will slow do so much that you turn the device on go out have several cigarettes, then walk in boils some water and go about making coffee for everyone in the office and then when that is finished walk back to your desk and wait another 15 minutes for Windows to open.

Several things cause that just turning the thing on is probably the worst because to use it it needs to be turned on. The next thing is installing software which messes things up no end and slows down the system. Cleaning the Temporary Files and not allowing the Windows Temp File to go crazy and limit it to a unreasonable size instead of allowing it to take up all the empty drive space is yet another thing that has to be done to keep Windows running somewhat like right.

Running software like Crap Cleaner regularly helps no end but it has it's limits and keeping the4 system clean from infections and the like not to mention regularly deleting all of the tracking cookies that you pick up is another thing that needs doing very regularly.

But even then it's best to wipe the drive and do a clean install of Windows every 18 moths to 2 years to keep peek performance, Windows is not a Set and Forget system it needs maintenance daily at the very least and the drives need defragging several times a day if performance is of any importance to you.

The best way to keep Windows working is to maintain the hell out of it and never stop and just as importantly DO NOT keep installing software as this just blotes the Registry and slows things down, do not keep large numbers of TABS open in any Browser and always close them when they are not needed, Do not have long file names or complex trees of file storage as the deeper the file is buried in the File Structure the longer it takes to recover or make any changes and NEVER be like one unit I saw recently with thousands of listings for files and programs left on the desktop this doesn't slow the thing down it cripples it tot he stage where you do not believe that it is doing anything at all.

As the Disk Usage has already been explained this happens because of Complexe File Structures, Long File Names, large numbers of files buried where they are commonly accessed or worse buried in File Structures more than 5 layers deep.